Definition and Classification

Pneumothorax is air in the pleural space causing lung collapse.

Clinical Features

• SUDDEN pleuritic chest pain and breathlessness, disproportionately severe in secondary pneumothorax
• Affected side: reduced expansion, HYPERRESONANCE, DIMINISHED OR ABSENT BREATH SOUNDS, reduced vocal fremitus and resonance
• Small pneumothoraces may have no signs

TENSION PNEUMOTHORAX — recognise clinically, treat immediately:

• Severe distress, hypoxia, agitation; TACHYCARDIA AND HYPOTENSION progressing to arrest
• TRACHEAL DEVIATION AWAY from the affected side; distended neck veins
• Rapid deterioration, particularly in a ventilated patient or after a procedure

Hydropneumothorax

Both air and fluid in the pleural space. Causes: ruptured tuberculous cavity (the commonest in India), ruptured lung abscess or empyema (pyopneumothorax), trauma, iatrogenic, bronchopleural fistula, oesophageal rupture, malignancy.

Classic signs:

• SHIFTING DULLNESS — the level of dullness changes with position
• A HORIZONTAL FLUID LEVEL on an ERECT chest X-ray (unlike the meniscus of a simple effusion) — the radiological hallmark
• SUCCUSSION SPLASH; "coin test"; bell tympany
• Dullness at the base with hyperresonance above; amphoric breathing above the fluid

Investigations

• CHEST X-RAY (erect, inspiratory) — a visible visceral pleural line with absent lung markings beyond it; an expiratory film is no longer routinely recommended
• BEWARE: in a supine patient air collects anteriorly and basally — the "deep sulcus sign"; pneumothorax is easily missed on a supine film
• Ultrasound — absent lung sliding, absent comet-tails, and the "lung point" sign; more sensitive than supine radiography
• CT chest — the gold standard; distinguishes bullae from pneumothorax (critical in COPD, where draining a giant bulla is disastrous)
• Investigate the cause — sputum for AFB and CBNAAT, HIV testing

Management

Tension Pneumothorax — Do Not Wait for a Chest X-ray.

IMMEDIATE NEEDLE DECOMPRESSION with a large-bore cannula — traditionally the second intercostal space mid-clavicular line, though the fourth or fifth space in the anterior axillary line is now often preferred as the chest wall is thinner there. Follow immediately with an intercostal drain.

Primary spontaneous: small and asymptomatic → conservative management with observation and high-flow oxygen (which accelerates reabsorption); large or symptomatic → needle aspiration, then chest drain if unsuccessful. Conservative management is increasingly favoured even for larger primary pneumothoraces in stable patients.

Secondary spontaneous: lower threshold — most require a chest drain and admission because of poor reserve.

Chest drain — inserted in the "safe triangle", above the rib, connected to an underwater seal; remove only after full expansion with no air leak for 24 hours.

Definitive management: VATS with bullectomy and PLEURODESIS for a second ipsilateral episode, a first contralateral episode, bilateral pneumothorax, persistent air leak beyond 3–5 days, or high-risk occupations (pilots, divers).

Advice: STOP SMOKING (markedly reduces recurrence), avoid air travel until resolution is confirmed, and NEVER SCUBA DIVE AGAIN after a spontaneous pneumothorax unless definitive surgery has been performed.

Hydropneumothorax: intercostal drainage with pleural fluid analysis (AFB, CBNAAT, ADA, cytology, culture) and treatment of the cause — antitubercular therapy for tuberculous hydropneumothorax, antibiotics and drainage for pyopneumothorax.

Definition

Dyspnoea is the subjective experience of breathing discomfort. Acute dyspnoea develops over minutes to hours. The immediate task is not diagnosis but identifying the few causes that will kill the patient within minutes.

Causes BY System

The "killers" to Exclude in the First Minutes

1. Upper airway obstruction / anaphylaxis — stridor, angio-oedema, urticaria

2. Tension pneumothorax — unilateral absent breath sounds, tracheal deviation, hypotension

3. Massive pulmonary embolism — sudden dyspnoea, hypoxia, hypotension, raised JVP with a clear chest

4. Acute pulmonary oedema — orthopnoea, crackles, raised JVP, frothy sputum

5. Cardiac tamponade — raised JVP, muffled sounds, hypotension, pulsus paradoxus

6. Acute severe asthma — silent chest, exhaustion

7. Myocardial infarction — particularly the silent presentation in diabetics and the elderly

Rapid Assessment

Simultaneous assessment and resuscitation — ABCDE, with oxygen, monitoring, access, ECG and oximetry from the outset.

History:

• speed of onset — seconds (pneumothorax, PE, foreign body, arrhythmia)
• minutes to hours (asthma, pulmonary oedema, anaphylaxis)
• days (pneumonia, effusion, anaemia). Associated chest pain, fever, wheeze, orthopnoea and PND, haemoptysis, urticaria. Precipitants — trigger exposure, drugs, sting, trauma, immobility or travel (PE), non-adherence. Past history.

Examination:

• conscious level, ability to speak in sentences, accessory muscle use, cyanosis, stridor (upper airway) versus wheeze (lower airway), urticaria.
• Respiratory rate — the most sensitive and most neglected vital sign
• SpO2, pulse, blood pressure, peak flow if asthma is suspected. Chest: tracheal position, expansion, percussion, breath sounds, added sounds. Cardiovascular: JVP, gallop, murmurs, oedema, calf swelling.

Investigations

Immediate: oximetry, ECG, capillary glucose, arterial blood gas (distinguishing type I from type II failure and identifying metabolic acidosis), and peak flow.

Urgent: chest X-ray, CBC, urea and electrolytes, D-dimer only if the pre-test probability of PE is low, troponin and BNP, cultures where sepsis is suspected.

Directed: bedside ultrasound and echocardiography — increasingly the single most useful investigation in the undifferentiated breathless patient (lung sliding, B-lines, pleural fluid, LV and RV function, IVC, pericardial fluid); CTPA; CT chest.

Management Principles

1. Airway, breathing, circulation — resuscitate before you diagnose

2. Oxygen — target 94–98%, or 88–92% in those at risk of CO2 retention

3. Immediate life-saving interventions:

• intramuscular adrenaline for anaphylaxis
• needle decompression for tension pneumothorax
• nebulised bronchodilators with steroids for asthma and COPD
• nitrates, diuretics and non-invasive ventilation for pulmonary oedema
• anticoagulation for PE
• pericardiocentesis for tamponade
• insulin and fluids for ketoacidosis

4. Non-invasive ventilation for cardiogenic pulmonary oedema and hypercapnic COPD — highly effective and often avoids intubation

5. Intubation for exhaustion, deteriorating gases, or failure of non-invasive support

6. Treat the cause and reassess after every intervention

Purpose

PFTs objectively measure lung volumes, airflow and gas exchange — to diagnose and classify disease (obstructive versus restrictive), assess severity and progression, evaluate treatment response, and provide pre-operative and disability assessment.

Lung Volumes

Key point: RV, FRC and TLC cannot be measured by spirometry, which measures only what can be exhaled.

Spirometry

Measures FVC, FEV1, the FEV1/FVC ratio, PEF and FEF 25–75% (small airway function, which falls early).

OBSTRUCTIVE causes: COPD, asthma, bronchiectasis, cystic fibrosis, bronchiolitis obliterans, upper airway obstruction.

RESTRICTIVE causes:

• Intrapulmonary: ILD and pulmonary fibrosis, sarcoidosis, pneumoconiosis, post-tuberculous fibrosis (important in India), ARDS, pneumonectomy
• Extrapulmonary: pleural — effusion, thickening; chest wall — kyphoscoliosis, ankylosing spondylitis, obesity; neuromuscular — Guillain–Barré syndrome, myasthenia, muscular dystrophy, motor neurone disease, phrenic palsy; ascites, pregnancy

Reversibility

Repeat 15–20 minutes after a bronchodilator. An increase in FEV1 of ≥ 12% AND ≥ 200 mL supports ASTHMA. COPD shows little reversibility and the ratio remains below 0.70 after bronchodilation — the diagnostic criterion.

Flow-volume Loops

Diffusing Capacity (dlco)

Reflects the surface area and thickness of the alveolar-capillary membrane and capillary blood volume.

Clinically valuable: DLCO distinguishes EMPHYSEMA (reduced) from ASTHMA (normal or raised), and ILD (reduced) from chest wall or neuromuscular restriction (normal). An isolated fall in DLCO with normal spirometry suggests pulmonary vascular disease.

Other Tests

Arterial blood gas; six-minute walk test (functional capacity and exertional desaturation); bronchial provocation for suspected asthma with normal spirometry; MIP/MEP and supine FVC for neuromuscular weakness (a supine fall > 20% indicates diaphragmatic weakness); cardiopulmonary exercise testing.

Practical Points

Results are effort-dependent — proper coaching and three acceptable reproducible manoeuvres are required. Interpret against Indian reference equations — Caucasian-derived predicted values overestimate Indian lung volumes by 10–15% and produce spurious "restriction". Contraindications: recent myocardial infarction, unstable angina, recent pneumothorax, recent eye or abdominal surgery, and haemoptysis of unknown cause.

Definition

Failure of the respiratory system to maintain adequate gas exchange: PaO2 < 60 mmHg and/or PaCO2 > 50 mmHg at sea level on room air.

By time course: ACUTE (low pH, no renal compensation); CHRONIC (near-normal pH with raised bicarbonate); ACUTE-ON-CHRONIC (raised bicarbonate with an acutely low pH). The distinction is made from the pH and bicarbonate and determines management.

Causes

TYPE I — problems within the lung: V/Q mismatch (commonest) — pneumonia, pulmonary oedema, PE, asthma, COPD; shunt — ARDS, consolidation, right-to-left cardiac shunt; diffusion impairment — ILD; reduced inspired oxygen — altitude.

TYPE II — problems with the ventilatory pump:

Clinical Features

Hypoxaemia: dyspnoea, tachypnoea, tachycardia, CENTRAL CYANOSIS (absent in severe anaemia), restlessness, agitation and confusion — often the earliest signs and frequently misread as anxiety; later bradycardia, hypotension, seizures, coma. Chronic: polycythaemia, pulmonary hypertension, cor pulmonale.

Hypercapnia (CO2 narcosis): WARM peripheries with a BOUNDING PULSE, FLAPPING TREMOR (asterixis), morning headache and papilloedema, drowsiness progressing to coma, conjunctival suffusion.

Also: accessory muscle use, intercostal recession, paradoxical abdominal movement (diaphragmatic fatigue — ominous), inability to speak in sentences, exhaustion.

Investigations

• ARTERIAL BLOOD GAS — the definitive test. Interpret systematically: pH → PaCO2 → PaO2 → bicarbonate → A–a gradient
• A–a gradient — normal ≈ (age/4) + 4 on air. A NORMAL gradient with hypoxaemia and hypercapnia indicates pure HYPOVENTILATION (drug overdose, neuromuscular disease); a RAISED gradient indicates intrinsic lung disease. This single calculation localises the problem
• Pulse oximetry — for monitoring; unreliable in poor perfusion and falsely reassuring in carbon monoxide poisoning and methaemoglobinaemia, and gives no information about CO2
• Chest X-ray, CBC, electrolytes, glucose, ECG, and cause-directed tests
• Serial FVC and single-breath count in neuromuscular causes

Management

1. Treat the cause — bronchodilators and steroids, antibiotics, diuretics, naloxone, immunotherapy, drainage.

2. Oxygen

• TYPE I: high-concentration oxygen, target SpO2 94–98%
• TYPE II or at risk of retention: CONTROLLED oxygen via Venturi mask, target 88–92%, with a repeat gas at 30–60 minutes
• Devices: nasal cannulae, simple mask, Venturi (fixed predictable FiO2 — the device of choice where control matters), non-rebreathing reservoir mask, and high-flow nasal oxygen

3. Ventilatory support

• NON-INVASIVE VENTILATION (BiPAP) — the treatment of choice for hypercapnic failure with acidosis (pH < 7.35) in COPD, and CPAP for cardiogenic pulmonary oedema. Reduces intubation, complications and mortality
• INVASIVE VENTILATION — for failure of or contraindication to NIV, coma, inability to protect the airway, haemodynamic instability, exhaustion, or refractory hypoxaemia
• Contraindications to NIV: arrest, unprotected airway, facial trauma, vomiting, severe agitation, undrained pneumothorax, instability

4. Supportive: treat bronchospasm and secretions, correct potassium, magnesium and phosphate (deficiency weakens respiratory muscles), nutrition, thromboprophylaxis, avoid sedatives.

5. Long-term: long-term oxygen therapy; domiciliary NIV for chronic hypercapnia in COPD, obesity hypoventilation and neuromuscular disease; rehabilitation; vaccination.

Definition

Abnormal accumulation of fluid in the pleural space. Normally 5–15 mL lubricates the pleural surfaces. About 500 mL is needed to blunt the costophrenic angle on an erect film, while ultrasound detects as little as 50 mL — which is why ultrasound is now standard.

Clinical Features

• Breathlessness, pleuritic pain (often preceding the effusion and easing as fluid separates the layers), dry cough
• Affected side: reduced expansion, STONY DULL percussion, DIMINISHED OR ABSENT BREATH SOUNDS, reduced vocal fremitus and resonance, and trachea and mediastinum shifted AWAY if large
• Bronchial breathing and egophony at the UPPER LEVEL from compressed lung
• Features of the cause — fever, weight loss and clubbing, orthopnoea and raised JVP, stigmata of liver disease

Light's Criteria

The fluid is an EXUDATE if ANY ONE is met:

1. Pleural : serum PROTEIN ratio > 0.5

2. Pleural : serum LDH ratio > 0.6

3. Pleural LDH > two-thirds of the upper limit of normal serum LDH

Sensitivity for exudates is ~98%, but about 25% of TRANSUDATES are misclassified as exudates — most often heart failure patients on DIURETICS, which concentrate the protein. Then use the serum–pleural ALBUMIN GRADIENT > 1.2 g/dL to identify a transudate.

Investigations

• Chest X-ray — blunting of the costophrenic angle, homogeneous opacity with a MENISCUS; massive effusion opacifies the hemithorax with mediastinal shift AWAY (shift towards indicates collapse, not effusion)
• ULTRASOUND — the investigation of choice: detects small effusions, identifies septations and loculation, and should guide every aspiration
• CT with contrast — parenchymal disease, malignancy, pleural thickening and nodularity, "split pleura" sign of empyema

DIAGNOSTIC PLEURAL ASPIRATION — mandatory for any undiagnosed effusion. Send for:

Pleural biopsy — Abrams' or image-guided for suspected TB (culture the biopsy, which raises yield); THORACOSCOPY with direct biopsy is the gold standard for undiagnosed exudates (yield > 90%).

Specific Entities

Tuberculous effusion — the commonest exudative effusion in young Indian adults: unilateral, lymphocytic, high protein, low glucose, raised ADA, and smear-negative with low culture yield. Treat with antitubercular therapy; drain only if large and symptomatic.

Parapneumonic effusion and empyema — simple (sterile, pH > 7.2 — antibiotics alone); complicated (pH < 7.2, glucose < 60 — requires drainage); empyema (frank pus — drainage plus antibiotics, with intrapleural tPA and DNase for loculation and surgical decortication for failure).

CHYLOTHORAX — milky fluid with triglycerides > 110 mg/dL and chylomicrons, from thoracic duct disruption:

• malignancy (lymphoma — commonest), trauma or surgery, tuberculosis and filariasis (relevant in India). Causes loss of protein, fat, fat-soluble vitamins and lymphocytes with malnutrition and immunosuppression.
• Management: treat the cause
• medium-chain triglyceride diet or TPN
• drainage
• octreotide
• thoracic duct ligation or embolisation. Distinguish from pseudochylothorax (chronic tuberculous or rheumatoid effusion — high cholesterol with crystals, low triglycerides).

Management

1. Treat the cause — diuretics, antitubercular therapy, antibiotics, management of malignancy

2. Therapeutic aspiration — remove no more than 1–1.5 litres at a sitting to avoid re-expansion pulmonary oedema

3. Intercostal drain for empyema, complicated parapneumonic effusion, haemothorax and large symptomatic malignant effusions

4. Recurrent malignant effusion: talc pleurodesis or an indwelling pleural catheter (often preferable with limited life expectancy)

5. Surgery — decortication for trapped lung or failed drainage

Allergic Bronchopulmonary Aspergillosis (abpa)

Definition: a hypersensitivity reaction to airway colonisation by *Aspergillus fumigatus*, occurring almost exclusively in asthma (1–2% of asthmatics) or cystic fibrosis. India has one of the highest reported burdens in the world, and it is a major under-diagnosed cause of "difficult" asthma.

Pathogenesis: *Aspergillus* colonises bronchial mucus without invading tissue, provoking combined type I (IgE) and type III (immune complex) hypersensitivity → eosinophilic inflammation, mucoid impaction, bronchial wall damage and CENTRAL BRONCHIECTASIS, progressing to fibrosis.

Clinical features:

• poorly controlled asthma despite adequate therapy
• recurrent wheeze, fever and weight loss
• expectoration of thick brown or blackish MUCUS PLUGS — highly characteristic
• haemoptysis
• recurrent "pneumonia" with fleeting infiltrates.

Diagnostic criteria (ISHAM): predisposing condition (asthma or CF) plus both obligatory criteria — positive *Aspergillus*-specific IgE and raised TOTAL SERUM IgE (typically > 1000 IU/mL) — plus at least two of: *Aspergillus* precipitins/IgG, compatible radiographic opacities, and eosinophils > 500/µL.

Radiology: fleeting infiltrates; CENTRAL (proximal) BRONCHIECTASIS with normal distal airways — highly characteristic; mucoid impaction with "FINGER-IN-GLOVE" opacities; HIGH-ATTENUATION MUCUS on CT (pathognomonic).

Management:

• ORAL CORTICOSTEROIDS — the mainstay, tapered over months, to control the immunological response and prevent bronchiectasis
• itraconazole or voriconazole to reduce fungal burden and spare steroids
• optimise asthma therapy
• omalizumab in refractory disease.
• Monitor total serum IgE — a fall of 25–50% indicates response and a rise heralds relapse.

Hypersensitivity Pneumonitis

Definition: immune-mediated inflammation of the lung PARENCHYMA and small airways from repeated inhalation of an organic antigen. Despite being allergic, peripheral eosinophilia is characteristically ABSENT — it is a type III and IV reaction with non-caseating granulomas and a lymphocytic alveolitis.

Clinical forms: ACUTE — 4–8 hours after heavy exposure, with fever, chills, dry cough and dyspnoea, mistaken for pneumonia or influenza, resolving in 24–72 hours if exposure ceases and recurring on re-exposure (the temporal relation to work or hobby is the key). CHRONIC — insidious dyspnoea, cough and weight loss from continuous low-level exposure, progressing to irreversible FIBROSIS.

Investigations:

• HRCT — ground-glass, centrilobular nodules and MOSAIC ATTENUATION with AIR TRAPPING
• chronic disease shows upper and mid-zone fibrosis (a useful contrast with the basal predominance of IPF).
• RESTRICTIVE spirometry with reduced DLCO.
• Serum precipitins indicate exposure, not disease.
• BAL: marked LYMPHOCYTOSIS (often > 50%).

Management:

• ANTIGEN AVOIDANCE IS THE DEFINITIVE TREATMENT — which may mean changing occupation or giving up birds.
• Corticosteroids hasten recovery in acute disease and are used in progressive chronic disease
• immunosuppressants and antifibrotics (nintedanib) for progressive fibrosis.

Tropical Pulmonary Eosinophilia (tpe)

Definition: a hypersensitivity response to microfilariae of *Wuchereria bancrofti* or *Brugia malayi* trapped and destroyed in the lungs — a distinctly Indian and South Asian diagnosis, repeatedly misdiagnosed and treated as asthma or tuberculosis for months or years.

Features: paroxysmal NOCTURNAL cough and wheeze (mirroring microfilarial periodicity), breathlessness, low-grade fever, weight loss.

Diagnostic combination — highly characteristic:

• MARKED EOSINOPHILIA — absolute count > 3000/µL
• VERY HIGH TOTAL IgE (> 1000 IU/mL)
• High antifilarial antibody titres
• ABSENCE of microfilariae in peripheral blood — they are sequestered and destroyed in the lung
• Diffuse bilateral reticulonodular shadowing on chest X-ray
• DRAMATIC RESPONSE TO DIETHYLCARBAMAZINE — both therapeutic and diagnostic

Management: diethylcarbamazine for 3 weeks; relapse in up to 20% may need repeat courses. Untreated, it progresses to interstitial fibrosis.

Other Pulmonary Eosinophilias

• LÖFFLER'S SYNDROME — transient migratory infiltrates with eosinophilia during pulmonary migration of *Ascaris*, hookworm, *Strongyloides*; self-limiting, treated with an anthelmintic
• Drug-induced — nitrofurantoin, sulphonamides, NSAIDs, phenytoin; resolves on withdrawal
• Eosinophilic granulomatosis with polyangiitis (Churg–Strauss) — asthma, eosinophilia and vasculitis; p-ANCA/MPO positive
• Chronic eosinophilic pneumonia — the "photographic negative of pulmonary oedema", responding dramatically to steroids

Definition

Permanent, abnormal, irreversible DILATATION AND DESTRUCTION of the bronchi, from chronic inflammation destroying the elastic and muscular wall components.

The engine is the "VICIOUS CYCLE" (Cole's hypothesis): an insult impairs mucociliary clearance → bacterial colonisation → chronic neutrophilic inflammation with proteases and elastase → further wall damage and dilatation → worse clearance. Breaking this cycle is the aim of all treatment.

Aetiology

Types: cylindrical (commonest, mildest), varicose, and cystic (saccular) — the most severe, classically post-tuberculous.

Clinical Features

• CHRONIC PRODUCTIVE COUGH with COPIOUS PURULENT SPUTUM — often foul-smelling, characteristically worse on waking and on changing posture
• Sputum separates into three layers on standing
• HAEMOPTYSIS in up to 50%; occasionally massive from hypertrophied bronchial arteries
• Recurrent infections, breathlessness, fatigue and weight loss
• Signs: CLUBBING, COARSE LOW-PITCHED INSPIRATORY CRACKLES that do NOT clear with coughing, wheeze, and in advanced disease cor pulmonale
• Colonising organisms: *H. influenzae* (commonest), *S. pneumoniae*, *Moraxella*, and *PSEUDOMONAS AERUGINOSA*, whose isolation marks more severe disease and worse prognosis

Investigations

• HIGH-RESOLUTION CT — the DIAGNOSTIC investigation (gold standard):
• "SIGNET RING SIGN" — internal bronchial diameter exceeds the accompanying artery
• Lack of normal tapering; visible bronchi within 1 cm of the pleura
• "TRAM-TRACK" thickened parallel walls; mucus plugging and "tree-in-bud" nodularity
• DISTRIBUTION is a clue: upper lobe — post-tuberculous, cystic fibrosis, ABPA; lower lobe — post-infective, aspiration, immunodeficiency; central — ABPA; right middle lobe and lingula — non-tuberculous mycobacteria
• Chest X-ray — insensitive; "tram-lines" and ring shadows; often normal in mild disease
• SPUTUM culture (bacterial, mycobacterial with AFB and CBNAAT, fungal) — repeatedly
• Spirometry — usually obstructive
• Investigate the CAUSE: immunoglobulins and IgG subclasses, *Aspergillus* IgE and total IgE, sweat chloride and CFTR testing, nasal nitric oxide and ciliary studies, alpha-1 antitrypsin, rheumatoid serology, HIV, and bronchoscopy where disease is localised

Management

• 1. AIRWAY CLEARANCE — the cornerstone, and the most under-prescribed treatment.
• Daily physiotherapy with postural drainage, active cycle of breathing, positive expiratory pressure and oscillating devices
• nebulised hypertonic saline. This is what breaks the vicious cycle and must be taught properly and done lifelong.

2. Antibiotics

• Exacerbations: a prolonged course (typically 14 days) guided by previous cultures; cover *Pseudomonas* where isolated
• Long-term macrolide (azithromycin) prophylaxis for ≥ 3 exacerbations per year — exclude non-tuberculous mycobacterial infection first, and monitor QT and hearing
• Nebulised antibiotics for chronic *Pseudomonas*; eradication therapy on first isolation

3. Treat the cause — immunoglobulin replacement, steroids and antifungals in ABPA, antitubercular therapy, removal of a foreign body, treatment of reflux.

4. General: smoking cessation, vaccination, pulmonary rehabilitation, bronchodilators where there is obstruction, nutrition. Inhaled corticosteroids are not routinely indicated unless asthma or COPD coexists.

5. Complications

• MASSIVE HAEMOPTYSIS — resuscitate, position the BLEEDING SIDE DOWN, correct coagulopathy, tranexamic acid, and BRONCHIAL ARTERY EMBOLISATION — the treatment of choice
• Surgical resection for localised disease with severe symptoms or recurrent haemoptysis
• Transplantation in advanced disease

Definition

A localised area of suppuration and necrosis within the lung parenchyma producing a cavity containing pus, usually with an air-fluid level. PRIMARY (normal lung, usually aspiration or immunosuppression) or SECONDARY (bronchial obstruction, septic embolism, adjacent spread); acute (< 6 weeks) or chronic.

Aetiology

1. ASPIRATION — by far the commonest mechanism. Risk factors are those causing impaired consciousness or swallowing: alcohol, general anaesthesia, seizures, stroke, head injury, drug overdose, dysphagia, reflux, nasogastric tubes, and POOR DENTAL HYGIENE AND PERIODONTAL DISEASE, which supplies the inoculum. Edentulous patients rarely develop anaerobic lung abscess — a useful pointer.

The SITE follows GRAVITY: supine — POSTERIOR SEGMENT OF THE RIGHT UPPER LOBE and SUPERIOR SEGMENT OF THE RIGHT LOWER LOBE; upright — basal segments. The RIGHT lung is affected more often because the right main bronchus is wider, shorter and more vertical.

2. Other mechanisms:

• bronchial obstruction by carcinoma (always consider malignancy in an older smoker), foreign body or nodes
• haematogenous — septic emboli in right-sided endocarditis and intravenous drug use (multiple bilateral peripheral cavities), Lemierre's syndrome
• direct extension — amoebic liver abscess rupturing into the chest is an important cause in India
• infection of a pre-existing cavity or bulla.

Organisms: ANAEROBES (commonest in aspiration) — usually polymicrobial oral flora; aerobes — *S. aureus* (including MRSA), *Klebsiella* (classically alcoholics and diabetics, with upper lobe cavitation and a "bulging fissure"), *Pseudomonas*, *Nocardia*. In India always consider *M. TUBERCULOSIS*, melioidosis, amoebic abscess and fungi.

Clinical Features

• INSIDIOUS onset over weeks in anaerobic abscess (acute in *Staphylococcus* and *Klebsiella*)
• High swinging fever with rigors, night sweats and marked weight loss
• Cough with COPIOUS FOUL-SMELLING (PUTRID) PURULENT SPUTUM — the foul odour is virtually diagnostic of ANAEROBIC infection
• A sudden large expectoration ("vomica") as the abscess ruptures into a bronchus
• HAEMOPTYSIS; pleuritic pain
• Signs: CLUBBING (may develop within weeks — unusually rapidly), anaemia, poor dentition; localised dullness, bronchial or amphoric breathing, coarse crackles

Investigations

• CHEST X-RAY — a cavity with a thick irregular wall and an AIR-FLUID LEVEL (visible only on an erect film), in the characteristic aspiration segments
• CT CHEST — superior; distinguishes abscess from empyema (abscess: thick irregular wall, acute angle with the pleura, no lung compression; empyema: smooth thin walls, obtuse angle, "split pleura", compressed lung), and identifies underlying obstruction or malignancy
• Sputum — Gram stain and culture, AFB, CBNAAT and mycobacterial culture (essential in India), fungal studies
• Blood cultures; CBC (neutrophil leucocytosis and anaemia), inflammatory markers, blood glucose, HIV testing
• BRONCHOSCOPY — indicated where there is suspected obstruction, atypical location, no response, or in any older smoker — to exclude carcinoma and foreign body
• Echocardiography for suspected septic embolism; amoebic serology and ultrasound where the right lower zone is involved

Differential of a Cavitating Lesion

Infective: lung abscess, TUBERCULOSIS (the commonest cause of a cavity in India), necrotising pneumonia, fungal (aspergilloma), melioidosis, hydatid. Malignant: cavitating squamous cell carcinoma, metastases. Vasculitic: granulomatosis with polyangiitis, rheumatoid nodules. Vascular: infarcted embolus.

Management

1. Prolonged antibiotics — the mainstay; most abscesses resolve medically

• Cover ANAEROBES and streptococci — a beta-lactam with beta-lactamase inhibitor, or clindamycin. Metronidazole must NOT be used alone, as it misses microaerophilic streptococci
• Duration is PROLONGED — typically 4–6 weeks or until radiological resolution; premature discontinuation is the commonest cause of relapse
• Antitubercular therapy if TB is confirmed or strongly suspected

2. Drainage — postural drainage and physiotherapy; percutaneous CT-guided catheter drainage for large abscesses (> 6–8 cm) or failure to respond after 5–7 days; bronchoscopic drainage in selected cases.

3. Surgery — rarely required; for failure of medical therapy, massive haemoptysis, suspected carcinoma, bronchopleural fistula or empyema requiring decortication.

4. Supportive and preventive — nutrition, glycaemic control, treatment of dental and periodontal disease (essential to prevent recurrence), management of dysphagia and reflux, alcohol cessation.

Definition

• Expectoration of blood from the respiratory tract below the larynx.
• MASSIVE (life-threatening) haemoptysis — variously > 200–600 mL in 24 hours, or any volume causing haemodynamic instability, airway obstruction or gas exchange impairment.
• The volume matters less than the effect: patients with massive haemoptysis DROWN — they do not exsanguinate, and this determines the entire approach.

HAEMOPTYSIS versus HAEMATEMESIS

Also exclude "pseudohaemoptysis" from the nasopharynx, gums or oropharynx — always examine the nose, mouth and throat.

Causes

In India the three commonest causes are TUBERCULOSIS, BRONCHIECTASIS and BRONCHOGENIC CARCINOMA — all three must be actively excluded.

Assessment

History:

• quantify the volume
• duration
• fever, night sweats and weight loss (TB, malignancy)
• chronic purulent sputum (bronchiectasis)
• pleuritic pain and dyspnoea (PE)
• orthopnoea (cardiac)
• smoking
• anticoagulants
• past TB.

Examination:

• haemodynamic status and oxygenation FIRST
• then clubbing, supraclavicular nodes, cachexia
• chest signs (a fixed monophonic wheeze suggests obstruction)
• cardiac signs of mitral stenosis
• nasal and oral examination
• signs of vasculitis (rash, sinusitis, haematuria).

Investigations

• CBC, coagulation profile, grouping and cross-match, renal function and urinalysis (haematuria and casts — pulmonary-renal syndrome)
• Chest X-ray — normal in 20–30%
• CT CHEST / CT ANGIOGRAPHY — the key investigation: identifies bronchiectasis, cavities, masses and aspergilloma, and maps the bronchial arterial supply for embolisation
• SPUTUM for AFB and CBNAAT (mandatory in India), bacterial and fungal culture, and cytology
• BRONCHOSCOPY — localises the bleeding side and allows therapeutic intervention; RIGID bronchoscopy is preferred in massive haemoptysis for suction, airway control and tamponade
• Echocardiography; CTPA for PE; ANCA, anti-GBM and ANA where alveolar haemorrhage is suspected (DLCO is characteristically RAISED in alveolar haemorrhage)

Management

MILD: treat the cause — antitubercular therapy, antibiotics, management of bronchiectasis or malignancy, review of anticoagulation; correct coagulopathy.

MASSIVE HAEMOPTYSIS — an emergency, in this order:

1. AIRWAY, BREATHING, CIRCULATION — high-flow oxygen, two large-bore cannulae, cross-match, correct coagulopathy, stop anticoagulants

2. POSITION THE PATIENT WITH THE BLEEDING SIDE DOWN (lateral decubitus) — the single most important immediate manoeuvre, protecting the healthy lung by gravity

3. PROTECT THE AIRWAY — early intubation with a large-bore tube; selective intubation of the non-bleeding lung or a double-lumen tube if expertise allows

4. TRANEXAMIC ACID — intravenous or nebulised

5. BRONCHOSCOPY — localise and apply local measures: iced saline lavage, topical adrenaline or tranexamic acid, balloon tamponade with a Fogarty catheter, endobronchial blockers

6. BRONCHIAL ARTERY EMBOLISATION — THE DEFINITIVE TREATMENT, controlling bleeding in 80–90%. Over 90% of massive haemoptysis arises from the high-pressure BRONCHIAL (systemic) circulation. Main risk: spinal cord infarction

7. SURGERY — for failure of embolisation or specific lesions (aspergilloma, AVM, trauma); high mortality as an emergency

Definition

ILD (diffuse parenchymal lung disease) comprises over 200 disorders characterised by inflammation and/or fibrosis of the lung INTERSTITIUM. The functional consequences are consistent: a RESTRICTIVE defect with REDUCED DLCO and exertional hypoxaemia.

Classification

Clinical Features

• PROGRESSIVE EXERTIONAL DYSPNOEA — the cardinal symptom, insidious over months to years, often attributed to age and so presenting late
• CHRONIC DRY COUGH — often distressing and refractory
• Signs: FINE END-INSPIRATORY "VELCRO" CRACKLES at the BASES — the classic sign and often the earliest abnormality; CLUBBING in ~50% of IPF and asbestosis, notably ABSENT in sarcoidosis and hypersensitivity pneumonitis; reduced expansion; cyanosis and cor pulmonale in advanced disease
• Extrapulmonary clues: skin thickening and Raynaud's (systemic sclerosis), joint deformity and nodules (rheumatoid), Gottron's papules and heliotrope rash (dermatomyositis), erythema nodosum and lupus pernio (sarcoidosis), sicca symptoms (Sjögren's), mechanic's hands

Investigations

1. HRCT — the central investigation, often diagnostic without biopsy. Pattern and distribution are the key:

2. Pulmonary function: RESTRICTIVE — reduced FVC and TLC with normal or raised FEV1/FVC, and REDUCED DLCO (often the earliest change and the best monitor of progression). Six-minute walk with oximetry demonstrates desaturation and is prognostic.

3. Bloods: autoimmune screen — ANA, ENA, rheumatoid factor, anti-CCP, myositis panel, ANCA; serum ACE and calcium; precipitins; eosinophil count; HIV and TB screening.

4. Bronchoscopy with BAL — lymphocytosis (sarcoidosis, HP, drug-induced), neutrophilia (IPF), eosinophilia; excludes infection and malignancy. Transbronchial, cryobiopsy or surgical (VATS) biopsy where uncertain.

5. MULTIDISCIPLINARY DISCUSSION — the current standard of care and the reference standard for diagnosis, bringing together physician, radiologist and pathologist.

6. Echocardiography for pulmonary hypertension.

Idiopathic Pulmonary Fibrosis

A chronic progressive fibrosing interstitial pneumonia of unknown cause, in older adults (> 60), commoner in men and smokers, with a UIP pattern. It carries the worst prognosis of the ILDs — median survival 3–5 years, comparable to many cancers. Acute exacerbations carry very high mortality.

Management

1. Treat the specific cause where one exists

• REMOVE THE ANTIGEN — occupational dusts, birds, mouldy hay; stop the causative drug; STOP SMOKING
• Immunosuppression for inflammatory and connective tissue disease-associated ILD — corticosteroids with mycophenolate, azathioprine, cyclophosphamide or rituximab
• Corticosteroids for sarcoidosis and for organising pneumonia (which responds dramatically)
• Antitubercular therapy for tuberculosis

2. ANTIFIBROTIC THERAPY — for IPF and progressive fibrosing ILD of any cause

PIRFENIDONE and NINTEDANIB slow the rate of FVC decline and are the standard of care in IPF; nintedanib is also approved for progressive fibrosing ILD and systemic sclerosis-associated ILD. They do not reverse fibrosis.

IMPORTANT: corticosteroids and immunosuppression are NOT indicated in IPF — the PANTHER-IPF trial showed prednisolone with azathioprine and N-acetylcysteine increased death and hospitalisation. Distinguishing IPF from inflammatory ILD therefore matters enormously, because the treatments are opposite.

3. Supportive care — central, not optional: long-term oxygen therapy, pulmonary rehabilitation, vaccination, treatment of reflux, management of cough, palliative care and advance care planning (consistently introduced too late), and LUNG TRANSPLANTATION — the only intervention that improves survival in IPF; refer EARLY, at diagnosis in suitable candidates.

Added Sounds

Voice-conducted Signs

All depend on one principle: solid consolidated lung conducts sound BETTER than air-filled lung; fluid and air in the pleural space conduct WORSE.

Other Signs

• BARREL CHEST — increased anteroposterior diameter, horizontal ribs, increased subcostal angle, from chronic HYPERINFLATION — COPD/emphysema, chronic severe asthma, cystic fibrosis; with hyperresonance and loss of cardiac and hepatic dullness
• TRACHEAL DEVIATION — TOWARDS the lesion: collapse, fibrosis, pneumonectomy (volume loss). AWAY: large effusion, TENSION pneumothorax, large mass. A displaced trachea in a breathless hypotensive patient means tension pneumothorax until proved otherwise
• CLUBBING — respiratory causes: bronchogenic carcinoma, mesothelioma, bronchiectasis, lung abscess, empyema, cystic fibrosis, ILD, asbestosis. NOT caused by uncomplicated COPD or asthma — its presence in a COPD patient demands a search for cancer, bronchiectasis or abscess
• HOOVER'S SIGN — paradoxical inward movement of the lower ribs on inspiration, from a flattened diaphragm
• PULSUS PARADOXUS — inspiratory fall in systolic pressure > 10 mmHg; in respiratory practice indicates acute severe asthma or COPD
• ASTERIXIS — CO2 retention (type II respiratory failure)
• SUCCUSSION SPLASH — HYDROPNEUMOTHORAX

Putting the Signs Together

Epidemiology and Aetiology

Lung cancer is the leading cause of cancer death worldwide and rising in India. Survival remains poor because most patients present with advanced disease.

Risk factors:

• SMOKING — responsible for 85–90%, proportional to pack-years; bidi and hookah carry comparable or greater risk; passive smoking is an established cause
• Occupational/environmental: ASBESTOS (MULTIPLICATIVE interaction with smoking), RADON, arsenic, chromium, nickel, silica, diesel exhaust, and INDOOR BIOMASS SMOKE — thought to underlie the substantial proportion of Indian lung cancer in non-smoking women
• Pre-existing lung disease — COPD, pulmonary fibrosis, and healed tuberculous scarring ("scar carcinoma")
• Family history; previous thoracic radiotherapy

Classification

Clinical Features

Local: cough — or a CHANGE in the character of a chronic smoker's cough, the finding that should trigger investigation; HAEMOPTYSIS; breathlessness; fixed monophonic wheeze or stridor; chest pain; recurrent or non-resolving pneumonia in the same lobe.

Regional (intrathoracic spread):

• SUPERIOR VENA CAVA OBSTRUCTION — facial and arm swelling, plethora, distended non-pulsatile neck veins, chest wall collaterals, positive Pemberton's sign
• HOARSENESS — left recurrent laryngeal nerve palsy
• Diaphragmatic paralysis — phrenic nerve involvement
• PANCOAST (superior sulcus) TUMOUR — invading the brachial plexus (C8/T1 — shoulder and arm pain with small hand muscle wasting), the sympathetic chain (HORNER'S SYNDROME), and ribs and vertebrae
• Dysphagia; pericardial effusion; pleural effusion

Metastatic: bone (pain, fracture, hypercalcaemia), brain (headache, seizures, focal deficit), liver, adrenals, and supraclavicular nodes — always palpate for them.

Constitutional: weight loss, anorexia, fatigue, cachexia.

PARANEOPLASTIC SYNDROMES: SIADH and ectopic ACTH (small cell); hypercalcaemia via PTHrP (squamous); Lambert–Eaton myasthenic syndrome, cerebellar degeneration and limbic encephalitis (small cell); hypertrophic pulmonary osteoarthropathy and clubbing (adenocarcinoma); dermatomyositis, acanthosis nigricans, migratory thrombophlebitis (Trousseau's). (See the paraneoplastic syndromes answer in Haematology & Oncology.)

Investigations

• Chest X-ray — mass, hilar enlargement, collapse, effusion, cavitation, raised hemidiaphragm. A normal film does NOT exclude lung cancer, particularly for central lesions
• CECT CHEST AND UPPER ABDOMEN (including adrenals), with brain imaging where indicated
• PET-CT — for staging and mediastinal nodal assessment; essential before radical treatment
• TISSUE DIAGNOSIS IS MANDATORY:
• BRONCHOSCOPY with biopsy, brushings and washings — central lesions
• CT-guided percutaneous biopsy — peripheral lesions
• EBUS-TBNA — mediastinal and hilar nodes, giving diagnosis and staging together
• Pleural fluid cytology and pleural biopsy; lymph node biopsy
• MOLECULAR AND IMMUNOHISTOCHEMICAL TESTING IS NOW ESSENTIAL in non-small cell disease: EGFR, ALK, ROS1, BRAF, KRAS G12C, RET, MET and PD-L1 expression — these determine eligibility for targeted and immune therapy, so obtaining adequate tissue is now a primary aim of the biopsy
• Staging: TNM for NSCLC; limited or extensive stage for SCLC
• Fitness assessment: pulmonary function with DLCO, performance status, comorbidity

Management

Non-small Cell:

• Early stage (I–II): SURGICAL RESECTION (lobectomy with nodal dissection) — the only reliably curative treatment, with adjuvant chemotherapy for higher-risk disease; stereotactic radiotherapy (SABR) if unfit for surgery
• Locally advanced (III): concurrent chemoradiotherapy followed by consolidation immunotherapy (durvalumab)
• Advanced (IV): treatment is directed by molecular profile — targetable driver mutation → TYROSINE KINASE INHIBITOR (osimertinib, alectinib), with survival far exceeding chemotherapy; no driver mutation → IMMUNOTHERAPY (pembrolizumab) alone or with chemotherapy, guided by PD-L1

SMALL CELL: chemotherapy (platinum with etoposide) plus immunotherapy; thoracic radiotherapy in limited stage; prophylactic cranial irradiation in selected responders. Surgery has almost no role. Highly chemosensitive initially but relapses, with poor prognosis.

Supportive and palliative care — integral, not an afterthought. Early palliative care improves both quality of life AND survival in advanced lung cancer. Includes analgesia, radiotherapy for bone pain, haemoptysis and SVC obstruction, endobronchial stenting for airway obstruction, pleurodesis or indwelling catheter for malignant effusion, dexamethasone for brain metastases and SVC obstruction, and management of breathlessness with opioids.

PREVENTION: smoking cessation is the single most effective measure; tobacco control policy; reduction of indoor biomass exposure; occupational protection. Low-dose CT screening reduces mortality in high-risk smokers but is not yet a national programme in India.

Definition

Chronic rheumatic heart disease (RHD) is permanent valvular damage resulting from one or more episodes of acute rheumatic fever, caused by the immune response to group A streptococcal pharyngitis. It remains the commonest form of acquired heart disease in children and young adults in India, and a leading cause of cardiac morbidity and premature death.

(The acute illness — acute rheumatic fever, the Jones criteria and secondary prophylaxis regimens — is covered in the Immunology & Rheumatology chapter. This answer deals with the chronic valve disease that follows.)

Pathogenesis of Chronic Valve Damage

Acute valvulitis causes oedema and verrucous vegetations along the line of closure. Over years, repeated inflammation and healing produce fibrosis, commissural fusion, chordal shortening and thickening, and calcification — converting a pliable valve into a rigid, stenotic and often regurgitant structure. Recurrent attacks of rheumatic fever accelerate this process, which is precisely why secondary prophylaxis matters more than any other intervention.

Valve involvement, in order of frequency:

• MITRAL VALVE — 70–80% (the most commonly affected)
• Aortic valve — 20–30%, usually with mitral involvement
• Tricuspid — uncommon and usually functional (secondary to right ventricular dilatation) rather than organic
• Pulmonary — very rare

Mitral stenosis is the classic and commonest chronic lesion, and the interval from acute rheumatic fever to symptomatic stenosis is typically 10–20 years — though it can be shorter in India, with severe disease appearing in adolescence ("juvenile mitral stenosis").

Clinical Features

• Often a silent latent period of years, with the patient presenting only when the valve lesion becomes haemodynamically significant.
• Symptoms of the specific valve lesion — exertional dyspnoea, orthopnoea, PND, fatigue, palpitations, haemoptysis (see the valvular heart disease answer).
• Atrial fibrillation — very common with mitral disease; often the presenting event, and a major cause of decompensation and stroke.
• Systemic embolism and stroke — a leading cause of disability, particularly in young women.
• Right heart failure — raised JVP, hepatomegaly, ascites, peripheral oedema — from pulmonary hypertension.
• Infective endocarditis superimposed on the damaged valve.
• Pregnancy — the increased blood volume and heart rate frequently unmask previously silent mitral stenosis, and RHD is a leading cause of maternal cardiac death in India.
• Growth retardation in children with severe long-standing disease.

Investigations

• ECHOCARDIOGRAPHY — the key investigation: identifies the valves involved, quantifies stenosis and regurgitation, assesses chamber size, ventricular function, pulmonary artery pressure and left atrial thrombus. It also detects subclinical rheumatic valve disease, which is the basis of echo-based screening programmes in endemic areas.
• ECG: P mitrale, atrial fibrillation, right or left ventricular hypertrophy.
• Chest X-ray: left atrial enlargement (double right heart border, splayed carina), pulmonary venous congestion, valve calcification, cardiomegaly.
• Bloods: CBC, ESR/CRP (to detect ongoing rheumatic activity), ASO titre, blood cultures if endocarditis is suspected, renal and liver function.
• Cardiac catheterisation — where echocardiography is inconclusive or before surgery in older patients (to assess the coronaries).

Management

1. SECONDARY PROPHYLAXIS — the single most important intervention

• Continuous antibiotic prophylaxis (intramuscular benzathine penicillin every 3–4 weeks, or oral penicillin) prevents recurrent attacks of rheumatic fever, each of which worsens valve damage.
• Duration depends on the presence of carditis and residual valve disease, and is often continued to the age of 40 or lifelong in established RHD (see the acute rheumatic fever answer for the schedule).
• Adherence over decades is the central practical challenge, and defaulting is the commonest reason for progressive valve destruction in Indian patients.

2. Medical management of the valve lesion and its complications

• Heart failure: diuretics, ACE inhibitors (caution in severe mitral or aortic stenosis), and salt restriction.
• Atrial fibrillation: rate control (beta-blocker, digoxin) and ANTICOAGULATION WITH WARFARIN — direct oral anticoagulants are NOT recommended in rheumatic mitral stenosis or with mechanical valves, a distinction of major practical importance.
• Infective endocarditis prophylaxis for the highest-risk patients, and meticulous dental hygiene for all.
• Treat anaemia, correct nutrition, and manage arrhythmias.

3. Intervention

• Percutaneous balloon mitral valvotomy — the treatment of choice for suitable mitral stenosis: pliable non-calcified valve, minimal regurgitation, no left atrial thrombus. It is relatively low-cost, avoids sternotomy, and is well suited to the young Indian patient population.
• Surgical valve repair or replacement — for unsuitable anatomy, mixed lesions, or predominant regurgitation. Mechanical valves last longer but require lifelong warfarin; bioprosthetic valves avoid anticoagulation but degenerate, which is a critical consideration in young women planning pregnancy, where warfarin is teratogenic — a decision requiring careful counselling.

4. Pregnancy and RHD

Pre-pregnancy counselling and risk assessment; balloon valvotomy before conception where indicated; joint cardiology-obstetric care; and careful anticoagulation planning, since warfarin is teratogenic in the first trimester but heparin gives poorer valve protection — a genuinely difficult balance requiring specialist management.

5. PREVENTION — the answer at population level

• Primary prevention: prompt diagnosis and antibiotic treatment of streptococcal sore throat, improved housing and reduced overcrowding, better nutrition and access to care.
• Secondary prevention: registers of RHD patients with organised delivery of penicillin prophylaxis — the model that has succeeded in other countries.
• Echo-based screening to detect subclinical disease in high-prevalence school populations.

Definition

Chronic coronary syndrome (formerly stable ischaemic heart disease) is the stable phase of coronary artery disease, characterised by reversible myocardial ischaemia occurring when oxygen demand exceeds supply, without acute plaque rupture.

Stable angina is chest discomfort that is:

1. Retrosternal, of characteristic quality and duration

2. Provoked by exertion or emotional stress

3. Relieved by rest or nitrates within minutes

Typical angina has all three features; atypical angina has two; non-anginal chest pain has one or none — a simple classification that determines pre-test probability and hence which test to order.

Pathophysiology

Fixed atherosclerotic stenosis limits coronary flow reserve. Symptoms typically appear when the lumen is narrowed by more than 70%. Ischaemia begins in the subendocardium, which is most vulnerable because it is perfused last and compressed during systole — producing ST depression on the ECG.

Determinants of myocardial oxygen demand: heart rate, contractility and wall stress (preload and afterload) — which is exactly why beta-blockers, which reduce heart rate and contractility, are so effective.

Other mechanisms of angina: microvascular angina (angina with normal coronaries), vasospastic (Prinzmetal) angina (rest pain with transient ST elevation, responsive to calcium channel blockers, precipitated by smoking and cocaine), and secondary angina from anaemia, thyrotoxicosis, aortic stenosis or arrhythmia.

Clinical Assessment

History — the most important tool: site, character (heaviness, tightness, constriction — patients often clench a fist over the sternum, "Levine's sign"), radiation, provoking and relieving factors, duration (minutes, not seconds or hours), and stability over time.

Canadian Cardiovascular Society (CCS) grading:

Examination is often normal but should assess: risk factors, anaemia, thyroid status, blood pressure, murmurs (aortic stenosis is a critical differential), signs of heart failure, and peripheral vascular disease and carotid bruits as markers of generalised atherosclerosis.

Differential diagnosis: acute coronary syndrome, aortic dissection, pericarditis, pulmonary embolism, gastro-oesophageal reflux and oesophageal spasm, musculoskeletal chest wall pain, and anxiety.

Non-invasive Testing for Myocardial Ischaemia

The choice of test depends on pre-test probability, the ability to exercise, the baseline ECG, and local availability.

Choosing the test:

• Low to intermediate probability, able to exercise, interpretable ECG → exercise ECG or CT coronary angiography
• Unable to exercise → pharmacological stress (dobutamine echo or vasodilator perfusion imaging)
• Abnormal baseline ECG → an imaging-based test
• High probability with limiting symptoms → proceed to invasive coronary angiography

Invasive coronary angiography remains the gold standard for anatomy, and fractional flow reserve (FFR) assesses the functional significance of intermediate lesions — an important refinement, since anatomical severity does not always equate to ischaemia.

Management

1. Anti-anginal therapy — to relieve symptoms

• Beta-blockers — first-line; reduce heart rate, contractility and demand.
• Calcium channel blockers — alternative or add-on; non-dihydropyridines (verapamil, diltiazem) reduce rate but must not be combined with beta-blockers (risk of bradycardia and heart block) or used in heart failure; dihydropyridines (amlodipine) are safe with beta-blockers.
• Nitrates — sublingual for acute relief and prophylaxis before exertion; long-acting for prevention, with a nitrate-free interval to prevent tolerance.
• Second-line: ivabradine (rate reduction in sinus rhythm), ranolazine, nicorandil, trimetazidine.

2. Disease-modifying therapy — to prevent events (the more important half)

• Antiplatelet — aspirin (clopidogrel if intolerant).
• High-intensity statin for all, irrespective of baseline cholesterol; add ezetimibe or a PCSK9 inhibitor to reach targets.
• ACE inhibitor — particularly with diabetes, hypertension, LV dysfunction or CKD.
• Optimal control of blood pressure, diabetes and weight.
• SMOKING CESSATION — the single most effective intervention.
• Cardiac rehabilitation and structured exercise; Mediterranean-type diet; stress management.

3. Revascularisation

• PCI with stenting — relieves symptoms effectively; in stable disease it improves symptoms but has not been shown to reduce mortality or infarction compared with optimal medical therapy in most patients (the COURAGE and ISCHEMIA trials) — an important point that examiners like and that patients deserve to be told.
• CABG (coronary artery bypass grafting) — improves survival in left main stem disease, three-vessel disease (especially with LV dysfunction or diabetes), and complex anatomy (high SYNTAX score).
• Decisions are made by a heart team, weighing anatomy, comorbidity and patient preference.

Definition and Classification

Cardiomyopathies are diseases of the myocardium associated with mechanical and/or electrical dysfunction, in the absence of coronary artery disease, hypertension, valvular disease or congenital heart disease sufficient to explain the abnormality.

Dilated Cardiomyopathy

The commonest cardiomyopathy. Characterised by dilatation and impaired contraction of one or both ventricles.

Causes:

• Idiopathic — a substantial proportion, many now recognised as genetic
• Genetic/familial — 30–50%; titin, lamin A/C and other mutations
• Toxic — ALCOHOL (a major and reversible cause), anthracyclines (doxorubicin — dose-dependent), trastuzumab, cocaine, amphetamines
• Infective — viral myocarditis (coxsackie, adenovirus, parvovirus B19), HIV, Chagas disease, diphtheritic myocarditis
• Metabolic and nutritional — thiamine deficiency (wet beriberi), selenium deficiency, hypocalcaemia, hypophosphataemia, thyroid disease
• PERIPARTUM CARDIOMYOPATHY — in the last month of pregnancy or the first 5 months postpartum; an important cause in India, with a risk of recurrence in subsequent pregnancies
• Tachycardia-mediated — from persistent uncontrolled tachyarrhythmia; reversible with rate control
• Autoimmune, sarcoidosis, haemochromatosis, muscular dystrophies

Clinical features: progressive heart failure (dyspnoea, orthopnoea, PND, oedema), fatigue, arrhythmias including atrial fibrillation and ventricular arrhythmias, thromboembolism from mural thrombus, and sudden cardiac death. Examination: displaced diffuse apex, S3 gallop, functional mitral and tricuspid regurgitation, raised JVP.

Investigations:

• ECG (non-specific — LBBB, arrhythmia, poor R wave progression), chest X-ray (cardiomegaly, pulmonary congestion), echocardiography (dilated ventricle with globally reduced EF), cardiac MRI for aetiology and scar, natriuretic peptides, and screening bloods (thyroid, iron studies, HIV, autoimmune).
• Coronary angiography to exclude ischaemic cardiomyopathy — an essential distinction.
• Genetic testing and family screening where familial disease is suspected.

Management:

• standard heart failure therapy — the four pillars (ARNI/ACE inhibitor, beta-blocker, MRA, SGLT2 inhibitor) with diuretics
• anticoagulation for AF or mural thrombus
• treat the cause — abstinence from alcohol (which can produce dramatic recovery), thiamine, rate control, stopping the offending drug
• ICD for primary prevention of sudden death
• CRT for broad QRS
• transplantation or mechanical support in end-stage disease.

Hypertrophic Cardiomyopathy

Definition: left ventricular hypertrophy (usually asymmetric, involving the interventricular septum) in the absence of a haemodynamic cause. It is the commonest inherited cardiac disorder (about 1 in 500) and the leading cause of sudden cardiac death in young people and athletes.

Genetics: AUTOSOMAL DOMINANT with variable penetrance, caused by mutations in sarcomeric proteins — beta-myosin heavy chain and myosin-binding protein C most commonly.

Pathophysiology: hypertrophy with myocyte disarray and interstitial fibrosis (the substrate for arrhythmia) causes:

• Diastolic dysfunction — a stiff, poorly relaxing ventricle
• LV OUTFLOW TRACT OBSTRUCTION in about a third (HOCM), caused by septal hypertrophy plus systolic anterior motion (SAM) of the mitral valve, which also produces mitral regurgitation
• Myocardial ischaemia — from increased demand, reduced capillary density and small vessel disease
• Arrhythmias — atrial fibrillation and ventricular arrhythmias

Clinical features: frequently asymptomatic and detected on screening or a murmur; exertional dyspnoea (the commonest symptom), angina, exertional syncope or presyncope — an ominous symptom, palpitations, and sudden cardiac death, characteristically during or just after exertion.

Signs:

• jerky, bisferiens carotid pulse
• double or triple apical impulse
• fourth heart sound
• EJECTION SYSTOLIC MURMUR at the left sternal edge, NOT radiating to the carotids
• pansystolic murmur of mitral regurgitation at the apex.

The dynamic murmur — a defining feature and a favourite examination question:

This is the opposite of aortic stenosis, where the murmur decreases with Valsalva — the key bedside discriminator.

Investigations:

• ECG is abnormal in over 90% — LVH, deep narrow Q waves in the inferolateral leads, T inversion (giant negative T waves in apical HCM)
• echocardiography — asymmetric septal hypertrophy, SAM, outflow gradient
• cardiac MRI for apical variants and fibrosis
• Holter monitoring for arrhythmia
• exercise testing for blood pressure response
• genetic testing and cascade screening of first-degree relatives.

Management:

• Avoid dehydration, and avoid drugs that reduce preload or afterload — nitrates, diuretics in excess, ACE inhibitors and digoxin — all of which worsen outflow obstruction.
• Beta-blockers first-line; verapamil as an alternative; disopyramide for refractory obstruction.
• Mavacamten — a cardiac myosin inhibitor and the first disease-specific therapy for obstructive HCM.
• Septal reduction therapy for drug-refractory obstruction — surgical myectomy or alcohol septal ablation.
• ICD for primary prevention in those at high risk (family history of sudden death, unexplained syncope, massive hypertrophy, non-sustained VT, abnormal blood pressure response to exercise, extensive fibrosis on MRI).
• AVOID COMPETITIVE SPORTS AND INTENSE EXERTION; treat atrial fibrillation with anticoagulation and rate or rhythm control.
• Screen all first-degree relatives — clinically, by ECG and echocardiography, and by genetic testing where the mutation is known.

Restrictive Cardiomyopathy

Definition: restrictive ventricular filling with normal or reduced diastolic volume, normal or near-normal systolic function and wall thickness — the ventricle is stiff and cannot fill.

Causes:

• Infiltrative — AMYLOIDOSIS (the commonest), sarcoidosis
• Storage — haemochromatosis, Fabry disease, glycogen storage disease
• Endomyocardial — ENDOMYOCARDIAL FIBROSIS (of major importance in tropical regions including parts of India and Africa), Löffler's endocarditis (hypereosinophilic), carcinoid, radiation, anthracyclines
• Idiopathic and familial

Clinical features:

• predominantly RIGHT heart failure — markedly raised JVP with prominent x and y descents, KUSSMAUL'S SIGN (a paradoxical rise in JVP on inspiration), hepatomegaly, ascites (often out of proportion to peripheral oedema), and oedema
• exercise intolerance and dyspnoea
• atrial fibrillation from biatrial enlargement
• thromboembolism.

RESTRICTIVE CARDIOMYOPATHY versus CONSTRICTIVE PERICARDITIS — a critical distinction, because constriction is surgically curable:

Investigations:

• ECG (low voltage complexes — classic in amyloidosis, conduction disease, arrhythmia)
• echocardiography (thickened ventricles with a "granular sparkling" myocardium in amyloid; biatrial enlargement; restrictive filling pattern)
• cardiac MRI
• endomyocardial biopsy where the diagnosis is uncertain
• investigation for the underlying systemic disease (serum free light chains and immunofixation for AL amyloidosis; bone scintigraphy for transthyretin amyloidosis; ferritin and transferrin saturation for haemochromatosis; serum ACE for sarcoidosis).

Management:

• treat the underlying cause (chemotherapy or transthyretin stabilisers such as tafamidis for amyloidosis, venesection for haemochromatosis, steroids for sarcoidosis and Löffler's)
• diuretics cautiously — these patients are preload-dependent and over-diuresis causes hypotension
• rate control and anticoagulation for atrial fibrillation
• avoid digoxin in amyloidosis (increased toxicity)
• surgical resection for endomyocardial fibrosis
• transplantation in selected cases.
• Prognosis is generally poor.

Acute Pericarditis

Definition: inflammation of the pericardium. Diagnosis requires at least 2 of 4 criteria:

1. Characteristic chest pain — sharp, pleuritic, worse on inspiration and lying flat, RELIEVED BY SITTING FORWARD

2. Pericardial friction rub — a superficial scratchy sound, best heard at the left sternal edge with the patient leaning forward, and characteristically evanescent (may come and go within hours)

3. Characteristic ECG changes — WIDESPREAD (concave, "saddle-shaped") ST ELEVATION with PR DEPRESSION, not confined to a coronary territory

4. New or worsening pericardial effusion

Causes:

• Idiopathic / viral (the commonest in developed settings) — coxsackie, echovirus, adenovirus, influenza, HIV
• TUBERCULOSIS — the commonest identifiable cause in India and the leading cause of constriction
• Bacterial (purulent) — staphylococcal, pneumococcal; often from adjacent infection or septicaemia
• Post-myocardial infarction — early (epistenocardiac) and late (Dressler's syndrome, autoimmune, at 2–6 weeks)
• Uraemia — an indication for dialysis
• Malignancy — lung, breast, lymphoma, mesothelioma
• Autoimmune — SLE, rheumatoid arthritis, scleroderma
• Post-cardiac surgery or radiation; trauma; drugs (hydralazine, procainamide, isoniazid)
• Hypothyroidism (usually with effusion)

Distinguishing pericarditis from STEMI on ECG — a common and important problem:

Management:

• NSAIDs or high-dose aspirin (preferred after myocardial infarction) as first-line, PLUS COLCHICINE — which significantly reduces recurrence and should be given routinely for several months
• restrict strenuous exercise until symptoms resolve and inflammatory markers normalise
• corticosteroids only for specific indications (autoimmune disease, uraemic pericarditis, or failure of first-line therapy), since steroids increase the risk of recurrence
• treat the underlying cause — antitubercular therapy with steroids for tuberculous pericarditis, drainage and antibiotics for purulent disease, dialysis for uraemia.

Pericardial Effusion

Accumulation of fluid in the pericardial space. The haemodynamic consequence depends on the RATE of accumulation, not the volume — a rapidly accumulating 200 mL can cause tamponade, while a slowly accumulating 1–2 litres may be tolerated because the pericardium stretches.

Features:

• may be asymptomatic
• dyspnoea, chest discomfort, muffled heart sounds, Ewart's sign (dullness with bronchial breathing below the left scapula from compression of the left lower lobe). Chest X-ray shows a globular, "water-bottle" cardiac silhouette (with a clear lung field, distinguishing it from heart failure)
• ECG shows low voltage complexes and, in large effusions, ELECTRICAL ALTERNANS (beat-to-beat variation in QRS amplitude as the heart swings within the fluid).
• Echocardiography is the definitive investigation.

Cardiac Tamponade

Definition: a life-threatening condition in which pericardial fluid raises intrapericardial pressure sufficiently to impair diastolic filling of the heart, reducing stroke volume and cardiac output.

Clinical features:

• BECK'S TRIAD: hypotension, raised JVP, and muffled heart sounds
• Tachycardia with a thready pulse; cool peripheries; oliguria
• PULSUS PARADOXUS — an inspiratory fall in systolic blood pressure of more than 10 mmHg (an exaggeration of the normal fall). It results from ventricular interdependence within a fixed pericardial space: inspiratory increase in right ventricular filling pushes the septum leftwards and reduces left ventricular filling.
• Raised JVP with a PROMINENT X DESCENT and an ABSENT Y DESCENT — because filling is restricted throughout diastole
• KUSSMAUL'S SIGN IS CHARACTERISTICALLY ABSENT in tamponade but PRESENT in constrictive pericarditis — a valuable discriminator
• Dyspnoea, agitation, and progression to shock and pulseless electrical activity

Investigations:

• ECHOCARDIOGRAPHY — urgent and diagnostic: pericardial effusion with diastolic collapse of the right atrium and right ventricle, a dilated non-collapsing inferior vena cava, and marked respiratory variation in mitral and tricuspid inflow. ECG — low voltage, electrical alternans.
• Do not delay treatment for imaging in a peri-arrest patient.

Management:

• URGENT PERICARDIOCENTESIS — the definitive, life-saving treatment, performed under echocardiographic guidance where possible; surgical drainage (subxiphoid window) for loculated, recurrent or malignant effusions and for purulent pericarditis.
• Intravenous fluids to maintain preload as a temporising measure.
• AVOID diuretics, vasodilators and positive-pressure ventilation, all of which reduce preload and can precipitate cardiovascular collapse.
• Send the fluid for cell count, protein, glucose, cytology, Gram stain, AFB with CBCNAAT, ADA and culture — the diagnostic yield is high and, in India, tuberculosis must always be sought.
• Treat the underlying cause and arrange follow-up; recurrence is common with malignancy.

Constrictive Pericarditis

Definition: a rigid, thickened, often calcified pericardium encases the heart and restricts diastolic filling. Unlike tamponade, filling in early diastole is unimpeded (the ventricle fills rapidly until it reaches the limit of the shell), then abruptly halts.

Causes:

• TUBERCULOSIS — the commonest cause in India and other endemic regions
• post-cardiac surgery
• mediastinal radiation
• recurrent viral or idiopathic pericarditis
• connective tissue disease
• uraemia
• purulent pericarditis.

Clinical features — predominantly RIGHT heart failure with a "normal-sized" heart:

• Marked raised JVP with PROMINENT X AND Y DESCENTS (the rapid y descent reflecting rapid early filling)
• KUSSMAUL'S SIGN — a paradoxical RISE in JVP on inspiration (the rigid pericardium prevents the right heart from accommodating increased venous return)
• PERICARDIAL KNOCK — an early diastolic sound as filling stops abruptly
• Hepatomegaly, ASCITES (often disproportionate to peripheral oedema), and peripheral oedema; cachexia in chronic cases
• Pulsus paradoxus is usually ABSENT or mild (in contrast to tamponade)
• Fatigue and exertional dyspnoea; atrial fibrillation

Investigations:

• chest X-ray — PERICARDIAL CALCIFICATION (best seen on the lateral film; virtually diagnostic when present, and classically tuberculous)
• ECG — low voltage, atrial fibrillation, non-specific T changes
• echocardiography — septal bounce, respiratory variation in ventricular filling, dilated IVC
• CT or cardiac MRI — the best demonstration of pericardial thickening and calcification
• cardiac catheterisation — equalisation of diastolic pressures with the "square root" or "dip and plateau" sign.

Management:

• PERICARDIECTOMY — the definitive and potentially CURATIVE treatment, and it should not be delayed until the patient is cachectic and has hepatic dysfunction, since operative mortality rises steeply with advanced disease.
• Antitubercular therapy with corticosteroids where tuberculosis is the cause — and in early tuberculous constriction, medical therapy alone may prevent progression. Diuretics provide symptomatic relief while awaiting surgery.

Definition

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterised by uncoordinated atrial activation with consequent deterioration of atrial mechanical function. It is the commonest sustained arrhythmia, and its prevalence rises steeply with age.

ECG features: absent P waves, replaced by fibrillatory (f) waves; an irregularly irregular ventricular response; and a narrow QRS complex unless there is aberrancy or pre-existing bundle branch block.

Classification: paroxysmal (self-terminating within 7 days), persistent (> 7 days or requiring cardioversion), long-standing persistent (> 1 year), and permanent (accepted, with no further attempts at rhythm control).

Aetiology

Also: heart failure, cardiomyopathy, pericarditis, congenital heart disease, obesity, and "lone AF" with no identifiable cause.

Clinical Features

• Palpitations, breathlessness, fatigue, reduced exercise tolerance, chest discomfort, dizziness and syncope.
• May be entirely asymptomatic and detected incidentally — or present for the first time with a stroke.
• Irregularly irregular pulse with a pulse deficit (apical rate exceeding radial rate, because weak beats do not transmit to the periphery).
• Loss of the atrial contribution to ventricular filling (about 20–30% of cardiac output) causes marked deterioration in patients with stiff ventricles — which is why AF so often precipitates decompensation in mitral stenosis, HFpEF and hypertrophic cardiomyopathy.
• Complications: STROKE and systemic embolism (a fivefold increased risk), heart failure, and tachycardia-mediated cardiomyopathy.

Investigations

• ECG (and Holter or event monitoring for paroxysmal AF)
• thyroid function
• CBC, electrolytes, magnesium, renal and liver function
• echocardiography (valve disease — especially mitral stenosis, chamber size, LV function, left atrial thrombus on transoesophageal imaging)
• chest X-ray
• investigation for precipitants (sepsis, pulmonary embolism, alcohol, sleep apnoea).

Management — Three Decisions

1. ANTICOAGULATION — the decision that saves lives

Assess stroke risk with CHA₂DS₂-VASc:

Anticoagulate men scoring ≥ 2 and women scoring ≥ 3 (consider at 1 and 2 respectively). Assess bleeding risk with HAS-BLED — to identify and correct modifiable risk factors, NOT to withhold anticoagulation.

Choice of agent:

• DOACs (apixaban, rivaroxaban, dabigatran, edoxaban) are preferred in NON-VALVULAR AF — comparable or better efficacy, less intracranial haemorrhage, no monitoring, fewer interactions.
• WARFARIN (target INR 2–3) IS MANDATORY in "VALVULAR" AF — that is, MODERATE-TO-SEVERE RHEUMATIC MITRAL STENOSIS and MECHANICAL PROSTHETIC VALVES. DOACs are contraindicated in these settings. This distinction is of major importance in India, where rheumatic AF is common.
• Left atrial appendage occlusion for patients with a genuine contraindication to long-term anticoagulation.
• Aspirin is NOT an acceptable alternative for stroke prevention in AF — an outdated practice that persists and leaves patients unprotected.

2. RATE versus RHYTHM CONTROL

• Rate control is appropriate for most older, minimally symptomatic patients: beta-blockers or non-dihydropyridine calcium channel blockers (diltiazem, verapamil — avoid in heart failure) first-line; digoxin as an adjunct or in sedentary patients and those with heart failure. Target a resting rate under about 110 (lenient) or under 80 (strict) depending on symptoms.
• Rhythm control — preferred in younger patients, those with symptoms despite rate control, new-onset AF, heart failure, or where AF is precipitated by a reversible cause. Recent evidence (EAST-AFNET 4) supports early rhythm control within a year of diagnosis to improve outcomes.
• Cardioversion: electrical (synchronised DC) or pharmacological (flecainide or propafenone in structurally normal hearts; amiodarone where there is structural disease). If AF has lasted more than 48 hours or is of unknown duration, anticoagulate for at least 3 weeks beforehand and 4 weeks afterwards, OR exclude left atrial thrombus with transoesophageal echocardiography — otherwise cardioversion can dislodge thrombus and cause a stroke.
• Catheter ablation (pulmonary vein isolation) — highly effective for symptomatic paroxysmal AF, and superior to drugs in selected patients including those with heart failure.

Treat the Underlying Cause and Risk Factors

Thyrotoxicosis, hypertension, heart failure, valve disease, sleep apnoea, obesity, alcohol excess — aggressive risk factor management substantially reduces AF burden and recurrence after ablation.

Digoxin — Uses, Toxicity and Management

Mechanism: inhibits the Na⁺/K⁺-ATPase pump, raising intracellular sodium and thereby intracellular calcium (via the sodium-calcium exchanger) — producing a positive inotropic effect. It also increases vagal tone, slowing conduction through the AV node — which is the basis of its rate-controlling action.

Uses: rate control in atrial fibrillation (particularly with heart failure or in sedentary patients — note it controls resting but not exertional rate) and symptom control in HFrEF (it reduces hospitalisation but does not improve survival).

Digoxin has a NARROW THERAPEUTIC INDEX, and toxicity is common and frequently missed.

Factors precipitating toxicity:

• HYPOKALAEMIA — the most important (potassium competes with digoxin for the pump; hypokalaemia increases binding). Also hypomagnesaemia and hypercalcaemia.
• Renal impairment — digoxin is renally excreted; doses must be reduced. Elderly patients with unrecognised renal impairment are the classic victims.
• Drug interactions — amiodarone, verapamil, quinidine, spironolactone, macrolides and itraconazole all raise digoxin levels.
• Hypothyroidism; low body weight; hypoxia.

Clinical features of toxicity:

Note the "reverse tick" or "Salvador Dali" sagging ST depression is a sign of digoxin EFFECT, not toxicity — it occurs at therapeutic levels and does not require action.

Management of digoxin toxicity:

1. STOP digoxin.

2. Correct electrolytes — particularly potassium and magnesium. (Note: in acute massive overdose, hyperkalaemia occurs and is a marker of severity; calcium must be avoided in that setting because of the risk of precipitating fatal arrhythmia.)

3. Continuous cardiac monitoring; treat bradyarrhythmias with atropine and temporary pacing if needed.

4. DIGOXIN-SPECIFIC ANTIBODY FRAGMENTS (Fab, "Digibind") — the specific antidote, indicated for life-threatening arrhythmia, haemodynamic instability, severe hyperkalaemia, or massive ingestion. Response is rapid and dramatic.

5. Avoid class Ia antiarrhythmics and cardioversion where possible (which may precipitate ventricular fibrillation in the digoxin-toxic heart); use lidocaine or phenytoin for ventricular arrhythmias if required.

6. Dialysis is ineffective — digoxin has a large volume of distribution.

Definition

Supraventricular tachycardias (SVTs) are tachyarrhythmias arising at or above the bundle of His, producing a narrow QRS complex (< 120 ms) unless there is aberrant conduction or pre-existing bundle branch block.

Classification

Clinical Features

Palpitations of abrupt onset and offset ("like a switch"), chest discomfort, breathlessness, dizziness, anxiety, polyuria after termination (from atrial natriuretic peptide release), and syncope if the rate is very fast or there is structural disease. Patients frequently describe neck pulsation ("frog sign") in AVNRT, from atrial contraction against a closed tricuspid valve.

Haemodynamic instability — hypotension, altered consciousness, ischaemic chest pain, acute heart failure — defines the emergency and dictates immediate cardioversion.

Management of Acute SVT

Step 1 — Assess for haemodynamic instability

If unstable: IMMEDIATE SYNCHRONISED DC CARDIOVERSION (with sedation). Do not delay for drugs.

Step 2 — If stable: VAGAL MANOEUVRES first

• Valsalva manoeuvre — and specifically the MODIFIED Valsalva (strain while semi-recumbent, then immediately lie flat with passive leg raise), which is substantially more effective than the standard technique and should be the default.
• Carotid sinus massage — one side at a time, for 5–10 seconds. Contraindicated with a carotid bruit, recent stroke or TIA, or known carotid disease.
• These terminate AVNRT and AVRT by transiently blocking the AV node, breaking the re-entrant circuit.

Step 3 — Drug therapy

• ADENOSINE — the drug of choice. Given as a rapid intravenous bolus into a large proximal vein followed by an immediate saline flush, with continuous ECG recording. Its half-life is under 10 seconds.
• Warn the patient beforehand — it causes brief but very unpleasant flushing, chest tightness, dyspnoea and a sense of impending doom, which resolves within seconds.
• Contraindications: asthma (bronchospasm), second- or third-degree heart block, and sick sinus syndrome without a pacemaker. Its effect is potentiated by dipyridamole and antagonised by theophylline and caffeine.
• Adenosine is diagnostic as well as therapeutic: it terminates AVNRT and AVRT, and by transiently blocking AV conduction it unmasks the underlying atrial activity in atrial flutter and atrial tachycardia.
• If adenosine fails: verapamil or diltiazem, or a beta-blocker (never combine intravenous verapamil with a beta-blocker).

Step 4 — Long-term management

• Avoid precipitants — caffeine, alcohol, stimulants, sleep deprivation.
• Beta-blockers or calcium channel blockers for prophylaxis.
• CATHETER ABLATION — highly effective and potentially CURATIVE for AVNRT, AVRT and atrial flutter, with high success rates and low complication rates; it is now first-line for symptomatic recurrent SVT and is preferred to lifelong drug therapy in young patients.

Antiarrhythmic Drugs — Vaughan Williams Classification

AMIODARONE — effective but toxic, and worth knowing in detail because it is so widely used:

• Effective for both atrial and ventricular arrhythmias, and safe in structural heart disease and heart failure — its major advantage.
• Very long half-life (weeks to months); extensive tissue distribution.
• Adverse effects: thyroid dysfunction (both hypo- and hyperthyroidism — it is iodine-rich), pulmonary fibrosis (the most feared), hepatotoxicity, corneal microdeposits (almost universal, usually harmless), slate-grey skin discoloration and photosensitivity, peripheral neuropathy, and bradycardia.
• Monitoring: thyroid and liver function every 6 months, chest X-ray, and ophthalmic review; warn about photosensitivity.
• Interactions: raises digoxin and warfarin levels substantially — reduce their doses when starting amiodarone.

Definition

Bradycardia is a heart rate below 60 beats per minute. It is pathological only when it causes symptoms or reflects underlying conduction disease — resting bradycardia is normal in athletes and during sleep.

Classification

1. Sinus node dysfunction (sick sinus syndrome)

• Sinus bradycardia, sinus pause or arrest, sinoatrial exit block
• TACHY-BRADY SYNDROME — alternating atrial tachyarrhythmia (usually AF) and bradycardia; treating the tachycardia unmasks or worsens the bradycardia, which is why these patients often need both a pacemaker and rate-controlling drugs
• Chronotropic incompetence — failure of the rate to rise appropriately with exercise

2. Atrioventricular block

Complete (third-degree) Heart Block

Definition: complete failure of conduction from atria to ventricles, so the ventricles are driven by an independent escape rhythm.

The escape rhythm determines the clinical picture:

Causes:

• Idiopathic fibrosis of the conduction system — Lev's disease (fibrosis of the fibrous skeleton, in the elderly) and Lenègre's disease (sclerodegenerative disease of the conduction system) — the commonest cause in older patients
• ISCHAEMIC — acute myocardial infarction: INFERIOR infarction causes block at the AV node (vagally mediated, narrow escape, often transient and atropine-responsive); ANTERIOR infarction causes block below the node from extensive septal necrosis (broad escape, unstable, poor prognosis, requires pacing)
• Drugs — beta-blockers, non-dihydropyridine calcium channel blockers, digoxin, amiodarone, ivabradine; and drug toxicity, especially digoxin
• Infective — rheumatic fever, DIPHTHERIA (an important and preventable cause in India), infective endocarditis with aortic root abscess, Lyme disease, Chagas disease, viral myocarditis
• Infiltrative — sarcoidosis, amyloidosis, haemochromatosis
• Congenital complete heart block — associated with maternal anti-Ro/La antibodies (neonatal lupus)
• Iatrogenic — cardiac surgery, catheter ablation, TAVI
• Metabolic — hyperkalaemia, hypothyroidism, hypothermia
• Increased vagal tone — athletes, sleep, vasovagal episodes

Clinical features:

• Fatigue, dizziness, exertional breathlessness, reduced exercise tolerance, confusion in the elderly
• STOKES–ADAMS ATTACKS — sudden transient loss of consciousness without warning, with pallor during the episode and flushing on recovery as circulation is restored; there is no aura and no post-ictal confusion, which distinguishes it from a seizure (though a prolonged pause may cause convulsive movements)
• Sudden cardiac death from asystole or ventricular arrhythmia
• Signs: slow, regular pulse (typically 30–40); CANNON 'a' WAVES in the JVP (right atrial contraction against a closed tricuspid valve) — a classic and highly specific sign of AV dissociation; VARIABLE INTENSITY OF THE FIRST HEART SOUND; wide pulse pressure; and sometimes a systolic murmur from increased stroke volume

Investigations

• 12-lead ECG — the diagnosis; assess the escape rhythm and QRS width.
• Ambulatory monitoring (Holter, event recorder, implantable loop recorder) for intermittent symptoms.
• Electrolytes — especially POTASSIUM, calcium and magnesium; renal function; thyroid function; digoxin level; cardiac troponin.
• Echocardiography — structural disease, infiltration, LV function.
• Investigate the cause — ischaemia, sarcoidosis (with cardiac MRI or PET), infective endocarditis (a new conduction defect in endocarditis indicates root abscess and mandates urgent surgical consideration), Lyme serology where relevant.

Management

1. Acute — for symptomatic or haemodynamically compromising bradycardia

• Airway, breathing, circulation; oxygen; intravenous access; continuous ECG monitoring.
• ATROPINE — first-line; effective for nodal block (narrow QRS escape) but often ineffective in infranodal block, and it may paradoxically worsen the situation by increasing atrial rate without improving conduction.
• If atropine fails: transcutaneous pacing (with analgesia and sedation — it is painful), and/or isoprenaline, adrenaline or dopamine infusion as a bridge.
• TEMPORARY TRANSVENOUS PACING for persistent haemodynamically significant block.
• STOP the offending drugs — beta-blockers, calcium channel blockers, digoxin; give specific antidotes (glucagon for beta-blocker overdose, calcium for calcium channel blocker overdose, digoxin Fab fragments for digoxin toxicity).
• Correct hyperkalaemia and other metabolic causes — a critical and easily reversible cause.
• Reperfusion for acute myocardial infarction.

2. Definitive — PERMANENT PACEMAKER

Indications:

• Third-degree (complete) AV block — symptomatic, or with a broad-complex or slow escape, or with asystolic pauses
• Mobitz type II second-degree block (regardless of symptoms)
• Symptomatic sinus node dysfunction, including tachy-brady syndrome requiring rate-controlling drugs
• Symptomatic bradycardia from an essential drug that cannot be withdrawn
• Alternating bundle branch block; block after anterior myocardial infarction
• Carotid sinus hypersensitivity with recurrent syncope

Do NOT pace reversible causes — drug-induced block, hyperkalaemia, hypothyroidism, Lyme carditis, or block complicating inferior infarction (which usually resolves) — until the cause has been treated and the block persists.

Pacemaker considerations: single-chamber (VVI) versus dual-chamber (DDD, which preserves AV synchrony and reduces "pacemaker syndrome"); conduction system pacing (His bundle or left bundle branch area pacing) is increasingly preferred to avoid the LV dysfunction that can follow chronic right ventricular apical pacing.

Definition

Cardiac arrest is the abrupt cessation of effective cardiac mechanical activity, confirmed by unresponsiveness, absent normal breathing (or only agonal gasps), and absent central pulse. Without immediate intervention, irreversible brain injury begins within 4–6 minutes.

RHYTHMS of Cardiac Arrest

VF is the commonest initial rhythm in out-of-hospital arrest from ischaemic heart disease, and carries the best prognosis — but it degenerates to asystole with time, which is why early defibrillation is the single most important determinant of survival.

REVERSIBLE CAUSES — THE 4 Hs AND 4 Ts

The Chain of Survival

1. Early recognition and call for help

2. Early high-quality CPR

3. Early defibrillation

4. Post-resuscitation care

Basic Life Support

1. Ensure safety of rescuer and victim.

2. Check responsiveness — shake and shout.

3. Open the airway (head tilt–chin lift; jaw thrust if cervical spine injury is suspected) and check breathing for no more than 10 seconds. Agonal gasping is NOT normal breathing and must not delay CPR — this is a common and fatal error.

4. Call for help and get a defibrillator.

Start Chest Compressions Immediately:

• Centre of the chest, lower half of the sternum
• Depth 5–6 cm; rate 100–120 per minute
• Allow FULL chest recoil between compressions
• MINIMISE INTERRUPTIONS — aim for a chest compression fraction above 60–80%
• Change the compressor every 2 minutes to prevent fatigue-related deterioration in quality

6. Compression:ventilation ratio 30:2 for untrained or single rescuers without an advanced airway; continuous compressions with asynchronous ventilation once an advanced airway is placed.

7. Compression-only CPR is acceptable and encouraged for untrained bystanders and where there is reluctance to give mouth-to-mouth — it is far better than no CPR.

Advanced Life Support

Shockable rhythm (VF/pVT):

• Defibrillate immediately — biphasic energy per device recommendation — and resume compressions immediately without a pulse check.
• 2 minutes of CPR, then rhythm check and further shock if indicated.
• Adrenaline after the third shock, then every 3–5 minutes.
• Amiodarone after the third shock (lidocaine as an alternative).
• Continue the 2-minute cycles; treat reversible causes throughout.

Non-shockable rhythm (PEA/asystole):

• Adrenaline as soon as possible, then every 3–5 minutes.
• CPR in 2-minute cycles with rhythm checks.
• Aggressively identify and treat the 4 Hs and 4 Ts — this is where survival lies, since there is no shock to give.

Airway and adjuncts: bag-mask ventilation initially; supraglottic airway or tracheal intubation by a skilled operator without interrupting compressions; waveform capnography — which confirms tube placement, monitors CPR quality (a rising ETCO₂ indicates better perfusion), and provides the earliest sign of return of spontaneous circulation (a sudden rise in ETCO₂).

Access: intravenous, or intraosseous if intravenous access is delayed or impossible.

POST-RESUSCITATION CARE (after return of spontaneous circulation)

• Airway and ventilation: aim for normoxia (SpO2 94–98% — AVOID hyperoxia, which worsens reperfusion injury) and normocapnia.
• Circulation: treat hypotension with fluids, inotropes and vasopressors; 12-lead ECG and urgent coronary angiography with PCI if a coronary cause is suspected.
• Targeted temperature management and strict avoidance of fever — hyperthermia after arrest worsens neurological outcome.
• Control seizures; maintain normoglycaemia; correct electrolytes.
• Neurological prognostication is deferred for at least 72 hours (and longer if sedation or hypothermia has been used) — early pessimism is unreliable and self-fulfilling.
• Identify and treat the underlying cause; consider ICD for survivors of VF/VT arrest not due to a reversible cause.

When to Stop

Decisions consider the duration of arrest, downtime before CPR, the initial rhythm, the response to resuscitation, end-tidal CO₂, comorbidity and the underlying cause. Prolonged resuscitation is justified in hypothermia, drowning, drug overdose, pregnancy and in children — and in thrombolysis for suspected pulmonary embolism, where CPR may be continued for 60–90 minutes.

Definition and Significance

The jugular venous pressure (JVP) is the vertical height of the column of blood in the internal jugular vein above the sternal angle, and reflects right atrial pressure — and therefore the filling pressure of the right heart. It is one of the most informative signs in clinical medicine, and one of the most poorly performed.

Why the INTERNAL jugular vein is used: it has no valves and lies in direct continuity with the right atrium, so it acts as a manometer. The external jugular vein is valved, tortuous and easily kinked, making it unreliable — though its distension may be used as a crude screen.

Technique

1. Patient reclined at 45 degrees, head turned slightly away from the side being examined, with the neck muscles relaxed.

2. Observe the right internal jugular vein, which lies deep to the sternocleidomastoid between its two heads — you observe the pulsation transmitted to the skin, not the vein itself.

3. Use tangential lighting, and measure the vertical height above the sternal angle.

4. Normal: 3–4 cm above the sternal angle (equivalent to a right atrial pressure of about 8–9 cm of blood, since the sternal angle lies roughly 5 cm above the right atrium).

Distinguishing Venous from Arterial Pulsation

The Waveform

The single most useful discriminator between tamponade and constriction: in tamponade the y descent is absent (filling is restricted throughout diastole), while in constriction the y descent is sharp and prominent (early filling is rapid until the rigid shell is reached).

Causes of a Raised JVP

• Right heart failure — from left heart failure, cor pulmonale, right ventricular infarction
• Fluid overload — excessive infusion, renal failure
• Tricuspid valve disease — regurgitation (giant v waves) and stenosis (giant a waves, slow y descent)
• CARDIAC TAMPONADE — with pulsus paradoxus and absent y descent
• CONSTRICTIVE PERICARDITIS — with Kussmaul's sign, prominent x and y descents, and pericardial knock
• Pulmonary hypertension and pulmonary embolism
• Superior vena cava obstruction — but here the JVP is RAISED AND NON-PULSATILE, with fixed distended neck veins, facial plethora and dilated chest wall collaterals — a key distinction
• Restrictive cardiomyopathy; complete heart block (cannon waves)

Causes of a LOW JVP: hypovolaemia — haemorrhage, dehydration, over-diuresis, third-space loss.

Special Signs

• KUSSMAUL'S SIGN — a PARADOXICAL RISE in JVP on inspiration (normally it falls, as negative intrathoracic pressure draws blood into the chest). Occurs when the right heart cannot accommodate increased venous return: CONSTRICTIVE PERICARDITIS (classical), restrictive cardiomyopathy, right ventricular infarction, severe right heart failure, and tricuspid stenosis. It is characteristically ABSENT in cardiac tamponade.
• Hepatojugular (abdominojugular) reflux — firm pressure over the right upper quadrant for 10–15 seconds produces a sustained rise in JVP of more than 3 cm, indicating that the right ventricle cannot accommodate the increased venous return; a sensitive sign of right heart failure and raised filling pressures.
• Pulsus paradoxus is measured with the sphygmomanometer, not seen in the JVP, but is closely associated — an inspiratory fall in systolic pressure of more than 10 mmHg in tamponade, severe asthma, COPD and massive pulmonary embolism.

Definition

Cyanosis is the bluish discoloration of the skin and mucous membranes resulting from an increased absolute concentration of deoxygenated (reduced) haemoglobin — conventionally more than 5 g/dL — in the capillary blood, or from the presence of abnormal haemoglobin pigments.

The critical point is that it depends on the ABSOLUTE amount of deoxygenated haemoglobin, not on the percentage saturation. Two consequences follow, and they are the most examined aspect of the topic:

• In POLYCYTHAEMIA, cyanosis appears EARLY and at a higher oxygen saturation, because 5 g/dL of deoxyhaemoglobin is reached more readily when total haemoglobin is high.
• In SEVERE ANAEMIA, cyanosis may NEVER appear, even with profound hypoxaemia — a patient with a haemoglobin of 5 g/dL cannot generate 5 g/dL of deoxyhaemoglobin. Absence of cyanosis therefore never excludes hypoxia.

Classification

Examine the tongue and buccal mucosa — this is the single most reliable way to distinguish central from peripheral cyanosis, since these are warm, highly vascular and unaffected by peripheral vasoconstriction.

Causes

Central Cyanosis:

1. Reduced inspired oxygen — high altitude

2. Respiratory disease with hypoxaemia:

• Ventilation-perfusion mismatch — COPD, pneumonia, asthma, pulmonary embolism (the commonest mechanism)
• Hypoventilation — respiratory depression, neuromuscular disease, obesity hypoventilation
• Diffusion impairment — interstitial lung disease, pulmonary oedema
• Shunt — ARDS, lobar collapse, pulmonary arteriovenous malformation

3. Cardiac — RIGHT-TO-LEFT SHUNT (characteristically does not improve with 100% oxygen):

• Tetralogy of Fallot (the commonest cyanotic congenital heart disease beyond infancy)
• Transposition of the great arteries, tricuspid atresia, truncus arteriosus, total anomalous pulmonary venous connection
• EISENMENGER SYNDROME — reversal of a left-to-right shunt (VSD, ASD, PDA) once pulmonary hypertension exceeds systemic pressure. In patent ductus arteriosus with Eisenmenger physiology, the cyanosis and clubbing are DIFFERENTIAL — affecting the toes but not the fingers, because desaturated blood enters the aorta distal to the origin of the head and arm vessels

4. Abnormal haemoglobins:

• METHAEMOGLOBINAEMIA — slate-grey cyanosis, unresponsive to oxygen, with a NORMAL PaO2 and a "saturation gap"; chocolate-brown blood. Causes: dapsone, local anaesthetics (prilocaine, benzocaine), nitrates and nitrites, aniline dyes, naphthalene, and contaminated well water in infants
• Sulfhaemoglobinaemia

5. Massive pulmonary embolism; severe pulmonary hypertension

Peripheral Cyanosis:

• Reduced cardiac output — heart failure, shock of any cause
• Cold exposure — physiological vasoconstriction (the commonest cause overall)
• Arterial occlusion — peripheral arterial disease, embolism, Raynaud's phenomenon
• Venous obstruction — deep vein thrombosis, superior vena cava obstruction
• Increased blood viscosity — polycythaemia
• All causes of central cyanosis also produce peripheral cyanosis

Clinical Assessment

History: duration (lifelong suggests congenital heart disease; acute suggests embolism, pneumothorax or methaemoglobinaemia), exertional symptoms, squatting in children (characteristic of tetralogy of Fallot), smoking and occupational exposure, drug and chemical exposure (methaemoglobinaemia), and family history.

Examination:

• distinguish central from peripheral by examining the tongue
• assess clubbing (present in cyanotic congenital heart disease, bronchiectasis, lung abscess, ILD and lung cancer — but NOT in uncomplicated COPD)
• examine for differential cyanosis
• assess respiratory and cardiovascular systems
• look for polycythaemia (plethoric facies, conjunctival suffusion) as a consequence of chronic hypoxia.

Investigations

• Pulse oximetry — a rapid screen. Note that it is falsely NORMAL in methaemoglobinaemia (plateauing around 85%) and falsely HIGH in carbon monoxide poisoning, because it cannot distinguish these pigments from oxyhaemoglobin.
• ARTERIAL BLOOD GAS — essential: measures PaO2 directly. A normal PaO2 with clinical cyanosis and a low measured saturation ("saturation gap") indicates an abnormal haemoglobin — methaemoglobinaemia.
• CO-OXIMETRY — measures methaemoglobin and carboxyhaemoglobin directly; the definitive test.
• CBC — polycythaemia (chronic hypoxia) or anaemia.
• Chest X-ray, ECG and echocardiography — for cardiac and respiratory causes; bubble contrast echocardiography to demonstrate a right-to-left shunt.
• THE HYPEROXIA TEST — administer 100% oxygen: PaO2 rises substantially in respiratory disease, but fails to rise significantly with a fixed right-to-left cardiac shunt. A simple bedside test that separates cardiac from pulmonary cyanosis.
• Pulmonary function tests, CT pulmonary angiography, and cardiac catheterisation as indicated.

Management

Treat the underlying cause — this is the whole of management:

• Oxygen therapy for hypoxaemic respiratory disease (with caution in COPD with CO2 retention — target 88–92%)
• Bronchodilators, antibiotics, ventilatory support as appropriate
• Anticoagulation or thrombolysis for pulmonary embolism
• Surgical or transcatheter correction of congenital heart disease; management of Eisenmenger syndrome with pulmonary vasodilators (and avoidance of pregnancy, which carries very high mortality)
• METHAEMOGLOBINAEMIA: remove the offending agent and give METHYLENE BLUE (contraindicated in G6PD deficiency, where ascorbic acid or exchange transfusion is used instead)
• Peripheral cyanosis: warm the part, improve cardiac output, treat arterial or venous obstruction

Peripheral Arterial Disease — Definition

Peripheral arterial disease (PAD) is obstruction of arterial blood supply to the limbs, most often from atherosclerosis of the lower limb arteries. It is both a cause of limb morbidity and, more importantly, a marker of generalised atherosclerosis — patients with PAD have a markedly increased risk of myocardial infarction and stroke, and most die of cardiovascular causes rather than of limb disease.

Causes of Obstructive Peripheral Vascular Disease

Clinical Features of Chronic Pad

• INTERMITTENT CLAUDICATION — cramping muscular pain precipitated by walking a reproducible distance and relieved within minutes by rest. The site indicates the level of disease: calf claudication → superficial femoral artery; thigh → common femoral or external iliac; buttock → aorto-iliac.
• LERICHE SYNDROME — aorto-iliac occlusion causing the triad of buttock and thigh claudication, absent femoral pulses, and erectile dysfunction.
• CRITICAL LIMB ISCHAEMIA — rest pain (typically nocturnal, in the forefoot, relieved by hanging the leg over the edge of the bed), ulceration and gangrene; indicates a threatened limb.
• Signs: absent or diminished pulses, cool pale limb, hair loss, shiny atrophic skin, thickened nails, prolonged capillary refill, arterial ulcers (painful, punched-out, on the toes, heel and lateral malleolus), Buerger's test (elevation pallor with dependent rubor), and reduced venous filling.

Fontaine classification: I — asymptomatic; II — intermittent claudication; III — rest pain; IV — ulceration or gangrene.

Arterial versus venous ulcers — a standard comparison:

Thromboangiitis Obliterans (buerger's Disease)

A non-atherosclerotic, segmental, inflammatory occlusive disease of small and medium arteries and veins of the limbs, with a strong and essentially obligatory association with TOBACCO USE. It typically affects young men (under 45), and is notably common in India, the Middle East and South-East Asia — where heavy smoking and bidi use begin early.

Features:

• distal ischaemia of the hands and feet with claudication of the foot arch and calf, rest pain, digital ulceration and gangrene
• migratory superficial thrombophlebitis (a highly characteristic feature)
• Raynaud's phenomenon
• normal proximal pulses with absent distal pulses. Angiography shows segmental occlusions with "corkscrew" collaterals and normal proximal vessels.

Management: ABSOLUTE AND COMPLETE CESSATION OF ALL TOBACCO — this is the only effective treatment, and continued smoking (even a few cigarettes, or smokeless tobacco) leads inexorably to amputation. Supportive care with wound management, analgesia, iloprost for critical ischaemia, and sympathectomy or bypass in selected patients — but no intervention substitutes for stopping tobacco.

Raynaud's Phenomenon

Definition: episodic, reversible vasospasm of the digital arteries and arterioles, provoked by cold or emotional stress, producing the classic TRIPHASIC COLOUR CHANGE:

1. WHITE (pallor) — vasospasm and ischaemia

2. BLUE (cyanosis) — deoxygenation of static blood

3. RED (rubor) — reactive hyperaemia on rewarming, often with burning pain and tingling

Causes of secondary Raynaud's:

• Connective tissue disease — SYSTEMIC SCLEROSIS (the commonest and most important; Raynaud's is often the first symptom, preceding other features by years), SLE, mixed connective tissue disease, dermatomyositis, rheumatoid arthritis, Sjögren's syndrome
• Occupational — VIBRATION WHITE FINGER from prolonged use of vibrating tools; cold exposure
• Obstructive arterial disease — atherosclerosis, Buerger's disease, thoracic outlet syndrome, cervical rib
• Drugs — beta-blockers, ergotamine, methysergide, cisplatin, bleomycin, ciclosporin, sympathomimetics
• Haematological — cryoglobulinaemia, cold agglutinin disease, polycythaemia, paraproteinaemia
• Others — hypothyroidism, hepatitis B and C, malignancy

Investigations

• Ankle-brachial pressure index (ABPI) — the key bedside test for PAD: normal 0.9–1.3; claudication 0.4–0.9; critical ischaemia < 0.4. Beware falsely HIGH or normal values (> 1.3) in DIABETICS and CKD from medial arterial calcification, which makes the vessels incompressible — use toe-brachial index or Doppler waveform analysis instead.
• Duplex ultrasound — first-line imaging; CT or MR angiography for planning intervention; catheter angiography where intervention is intended.
• Exercise treadmill testing with post-exercise ABPI where the diagnosis is uncertain.
• For Raynaud's: nailfold capillaroscopy (the key discriminator), ANA and extractable nuclear antigens, ESR, CBC, thyroid function, cryoglobulins, and hepatitis serology.
• Cardiovascular risk assessment for all — lipids, glucose and HbA1c, renal function, ECG.

Management

Peripheral arterial disease:

1. RISK FACTOR MODIFICATION — the priority, because these patients die of heart attacks and strokes, not of their legs: smoking cessation (the single most important intervention), statin therapy for all, antiplatelet therapy, blood pressure and diabetes control.

2. SUPERVISED EXERCISE PROGRAMME — the most effective treatment for claudication, improving walking distance as much as revascularisation in many patients by promoting collateral development. Consistently under-prescribed.

3. Cilostazol for symptomatic claudication (contraindicated in heart failure).

4. Foot care — daily inspection, appropriate footwear, prompt treatment of injury and infection; podiatry, particularly in diabetics.

5. REVASCULARISATION — angioplasty with or without stenting, or surgical bypass — for critical limb ischaemia, disabling claudication refractory to conservative treatment, and tissue loss.

6. Amputation — for irreversible gangrene, uncontrolled infection or intractable pain.

Raynaud's phenomenon:

• Keep the whole body warm, not just the hands — gloves, layers, hand warmers; avoid sudden cold exposure.
• STOP SMOKING — absolutely essential; avoid beta-blockers and other precipitating drugs.
• Calcium channel blockers (nifedipine, amlodipine) — first-line drug treatment.
• Phosphodiesterase-5 inhibitors (sildenafil); topical nitrates; ARBs and SSRIs as alternatives.
• Severe or ulcerating disease: intravenous iloprost, bosentan (which prevents new digital ulcers in systemic sclerosis), digital sympathectomy, botulinum toxin injection.
• Treat the underlying disease in secondary Raynaud's, and monitor for evolving connective tissue disease.