Quick Answer
Cardiomyopathies and pericardial diseases are a NEET PG cluster where morphology, murmurs and manoeuvres pay off.
- Dilated CMP — dilated LV, reduced EF, systolic failure; GDMT plus ICD if EF less than 35 percent.
- Hypertrophic CMP — sarcomeric mutations; commonest cause of SCD in young athletes; murmur louder on Valsalva; treat with beta-blockers, myectomy or mavacamten.
- Restrictive CMP — impaired filling with normal EF; amyloid, sarcoid, EMF (tropical India), haemochromatosis.
- ARVC — desmosomal genes, fibrofatty RV, epsilon wave, SCD in athletes.
- Acute pericarditis — sharp positional pain, friction rub, diffuse ST elevation with PR depression; NSAIDs plus colchicine.
- Tamponade — Beck's triad, pulsus paradoxus, RV diastolic collapse; urgent pericardiocentesis.
- Constriction — post-TB in India, Kussmaul sign, pericardial knock and calcification; pericardiectomy.
Cardiomyopathies and pericardial diseases account for a disproportionate share of NEET PG cardiology stems because they combine bedside signs, dynamic manoeuvres, echocardiography and India-specific epidemiology (TB pericarditis, endomyocardial fibrosis, rheumatic contribution) into a single testable package.
This NEETPGAI deep dive covers the four cardiomyopathies, the three pericardial syndromes and the physiological reasoning that separates them. Combine it with the heart failure and GDMT guide for pharmacology overlap and with the rheumatic heart disease guide for the valve pathology that still drives half of Indian cardiology admissions.
Dilated cardiomyopathy (DCM)
DCM is defined as left ventricular dilatation with systolic dysfunction (EF less than 40 percent) in the absence of abnormal loading conditions or coronary artery disease sufficient to cause it. Prevalence is around 1 in 250.
Aetiology — idiopathic and familial (up to 35 percent, titin truncating variants commonest), ischaemic cardiomyopathy (post-MI remodelling — strictly a DCM phenocopy excluded from the primary definition, though the single largest global contributor to a dilated hypokinetic LV), viral post-myocarditis (coxsackie B, parvovirus B19, HHV-6, SARS-CoV-2), alcohol, cocaine, chemotherapy (anthracyclines with cumulative dose dependence, trastuzumab), peripartum (final month of pregnancy to five months post-partum), endocrine (thyrotoxicosis, acromegaly, phaeochromocytoma), tachycardia-induced, nutritional deficiency (thiamine, selenium, carnitine) and haemochromatosis.
Presentation — heart failure symptoms (dyspnoea, orthopnoea, PND, oedema), atrial and ventricular arrhythmias, systemic and pulmonary thromboembolism from mural thrombus, mitral regurgitation from annular dilatation.
Investigations — ECG (LBBB, non-specific ST-T changes), chest X-ray (cardiomegaly with cardiothoracic ratio over 0.5), echocardiography (dilated LV, reduced EF, functional MR), cardiac MRI (fibrosis pattern helps differentiate from ischaemic), coronary angiography to exclude CAD, genetic panel if familial pattern, endomyocardial biopsy in select cases.
Management — full guideline-directed medical therapy (GDMT — ARNI/ACEi, beta-blocker, MRA, SGLT2 inhibitor), device therapy (ICD for primary prevention if EF 35 percent or less despite 3 months of GDMT and NYHA II or III; CRT if QRS 130 ms or more with LBBB), advanced therapy (LVAD, cardiac transplantation), treat the specific cause (abstinence in alcohol, iron chelation, thiamine replacement, bromocriptine and heart failure therapy in peripartum).
Hypertrophic cardiomyopathy (HCM)
HCM is the commonest inherited cardiovascular disease (prevalence 1 in 500) and the leading cause of sudden cardiac death in young athletes and adolescents. Autosomal dominant with variable penetrance, driven by mutations in sarcomeric protein genes — most commonly beta-myosin heavy chain (MYH7) and myosin-binding protein C (MYBPC3).
Morphology — asymmetric septal hypertrophy is the classic pattern; concentric, apical (Yamaguchi variant, common in Japan and India), midcavity and mass-like forms exist. LV wall thickness of 15 mm or more in adults (13 mm if familial) defines HCM.
Pathophysiology of LVOT obstruction — septal hypertrophy narrows the outflow tract; systolic anterior motion (SAM) of the anterior mitral leaflet against the septum produces a dynamic sub-aortic gradient and posteriorly directed mitral regurgitation.
Clinical features — often asymptomatic and detected on family or pre-participation screening; exertional dyspnoea, angina, presyncope, syncope and sudden death. Bifid ("spike-and-dome") carotid pulse, prominent apex, S4, and a harsh crescendo-decrescendo systolic murmur at the left lower sternal border are typical.
Dynamic manoeuvres — the murmur increases with Valsalva strain, standing and amyl nitrite (reduce preload/afterload, worsen obstruction) and decreases with squatting, passive leg raise and handgrip. This is opposite to aortic stenosis.
Investigations — ECG shows LVH plus deep narrow Q waves in inferolateral leads, giant negative T waves in apical HCM; echocardiography is diagnostic; cardiac MRI quantifies fibrosis (late gadolinium enhancement) which predicts SCD risk; genetic testing informs family screening.
Sudden cardiac death risk stratification uses HCM Risk-SCD (or ESC calculator) — family history of SCD, unexplained syncope, non-sustained VT on Holter, maximum wall thickness of 30 mm or more, LVOT gradient, left atrial size and age.
Treatment — first-line beta-blockers (metoprolol, bisoprolol) or non-dihydropyridine calcium channel blockers (verapamil) for symptoms; disopyramide added for refractory obstruction; septal reduction therapy (surgical myectomy or alcohol septal ablation) for drug-refractory symptomatic obstruction; ICD for high SCD risk; mavacamten (cardiac myosin inhibitor, FDA approved 2022) reduces LVOT gradient and defers septal reduction in obstructive HCM. Avoid pure vasodilators, diuretics in excess and digoxin.
Restrictive cardiomyopathy (RCM)
RCM is characterised by impaired ventricular filling with preserved systolic function and normal ventricular size — the diastolic-failure analogue of DCM.
Causes — infiltrative (amyloidosis is now the commonest identified cause after routine bone-tracer scanning; sarcoidosis; haemochromatosis), storage (Fabry, glycogen), endomyocardial (endomyocardial fibrosis in tropical India, Loffler endocarditis in temperate hypereosinophilia), post-radiation, idiopathic and familial (TNNI3 mutations).
Amyloidosis subtypes — AL (light-chain), ATTR wild-type (senile, in men over 70), ATTR hereditary (V122I, characteristic of West African ancestry). Suspect in any elderly patient with heart failure and preserved EF plus low-voltage ECG paradoxical to LVH on echo, apical sparing on strain, tongue macroglossia (AL), and bilateral carpal tunnel history. Bone-tracer PYP scan is highly sensitive for ATTR. Treat with tafamidis for ATTR, chemotherapy or autologous stem cell transplant for AL.
Endomyocardial fibrosis (EMF) — dense fibrosis of the RV or LV endocardium, obliterating the ventricular apex; commonest in Kerala and coastal India, and sub-Saharan Africa; presents with biventricular restrictive physiology, AV valve regurgitation, apical thrombus and heart failure. Sree Chitra Tirunal Institute in Trivandrum leads Indian surgical management (endomyocardectomy plus valve repair).
Clinical, investigation and management — Kussmaul sign may be present; biatrial enlargement on echo with normal ventricular size; restrictive filling on Doppler; cardiac MRI shows infiltration and fibrosis; treat the underlying disease; symptomatic diuresis; consider transplantation for select cases.
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
ARVC is a genetic desmosomal disease (plakophilin-2 most common gene) with progressive fibrofatty replacement of the RV free wall, ventricular arrhythmias and sudden death — a top cause of exercise-related SCD in young athletes (particularly Italian and Indian series).
- ECG — epsilon wave (low-amplitude signal after QRS in V1 to V3), T-wave inversion V1 to V3 in adults, prolonged terminal activation.
- Imaging — cardiac MRI shows RV dilatation, wall motion abnormalities and fibrofatty infiltration.
- Task Force criteria integrate imaging, tissue, ECG, arrhythmia, family history and genetics.
- Management — exercise restriction, beta-blockers, ICD for primary or secondary prevention in high-risk patients, catheter ablation for refractory VT, cardiac transplant end-stage.
Acute pericarditis
Aetiology — viral (coxsackie B, echovirus, adenovirus) is commonest globally; post-MI (early "epistenocardic" within 4 days and late Dressler at 2 to 8 weeks); uraemic; autoimmune (SLE, RA, systemic sclerosis, familial Mediterranean fever); malignancy; radiation; and — critical for India — tuberculosis, which remains a leading cause of pericardial disease locally.
Clinical features — sharp retrosternal chest pain worsened by inspiration and lying flat, relieved by leaning forward; pericardial friction rub (scratchy, best heard at left sternal border with patient sitting up and leaning forward); low-grade fever.
ECG stages — Stage 1: diffuse concave-upwards ST elevation with PR depression; Stage 2: normalisation; Stage 3: diffuse T-wave inversion; Stage 4: normalisation. PR depression and diffuse (rather than territorial) ST elevation differentiate pericarditis from STEMI.
Investigations — ECG, troponin (elevated in myopericarditis), echocardiography for effusion, CRP for monitoring, chest X-ray, TB work-up in high-prevalence settings.
Treatment — NSAIDs (ibuprofen 600 to 800 mg TDS or high-dose aspirin 750 to 1000 mg TDS post-MI) plus colchicine 0.5 mg BD for 3 months (halves recurrence — COPE and ICAP trials). Steroids reserved for autoimmune, uraemic or refractory disease. Recurrence occurs in around 30 percent; add anakinra or rilonacept for colchicine-refractory recurrent pericarditis (RHAPSODY trial).
Cardiac tamponade
Tamponade is life-threatening compression of the heart by pericardial fluid, restricting diastolic filling and reducing cardiac output.
- Clinical — Beck's triad (hypotension, muffled heart sounds, elevated JVP) is only present in a minority; pulsus paradoxus (inspiratory fall in systolic BP over 10 mmHg) is more reliable; electrical alternans on ECG; total electrical alternans (QRS and T amplitudes alternating) is highly specific.
- Echocardiography — diagnostic. Diastolic collapse of the RV free wall, systolic collapse of the right atrium, IVC plethora (dilated, no respiratory variation) and greater than 25 percent respiratory variation in mitral inflow.
- Treatment — urgent pericardiocentesis under echo guidance via the subxiphoid approach; surgical drainage in loculated or purulent effusions; IV fluids to bridge to drainage; avoid mechanical ventilation which worsens haemodynamics.
In India, TB and malignant effusions are the commonest large chronic effusions and drive many pericardial windows.
Constrictive pericarditis
Constriction results from a thickened, fibrotic, sometimes calcified pericardium that restricts diastolic filling despite normal ventricular contractile function.
- Aetiology in India — tuberculosis is still the leading cause; globally, post-cardiac surgery and post-radiation dominate.
- Clinical — right-sided heart failure predominance (raised JVP, hepatomegaly, ascites, peripheral oedema); Kussmaul sign (paradoxical JVP rise on inspiration); pericardial knock (early diastolic sound).
- Imaging — chest X-ray may show pericardial calcification; echocardiography shows a septal bounce, respiratory interventricular dependence, dilated IVC; cardiac MRI or CT confirms pericardial thickening; catheterisation shows equalisation of end-diastolic pressures and "dip-and-plateau" (square-root sign).
- Treatment — pericardiectomy is definitive; medical therapy (loop diuretics, treatment of TB) can bridge or be sole therapy in transient constriction.
NEET PG MCQ traps
- Peripartum cardiomyopathy — last month of pregnancy to five months post-partum; bromocriptine in select cases.
- HCM murmur — louder on Valsalva, softer on squatting; opposite to AS.
- Sudden cardiac death in young athletes — HCM commonest in USA and India; ARVC in Italy.
- Mavacamten — cardiac myosin inhibitor for obstructive HCM (2022).
- Amyloid cardiomyopathy — low-voltage ECG paradoxical to LVH; apical sparing on strain; PYP scan for ATTR.
- Endomyocardial fibrosis — Kerala, Odisha, sub-Saharan Africa; apical obliteration.
- Loffler endocarditis — temperate zone hypereosinophilic equivalent of EMF.
- Epsilon wave — ARVC.
- Dressler syndrome — 2 to 8 weeks post-MI, autoimmune pericarditis.
- Colchicine in pericarditis — halves recurrence (COPE and ICAP trials); 3-month course.
- Steroids in acute pericarditis — increase recurrence; use only for autoimmune or refractory disease.
- Beck's triad — insensitive; look for pulsus paradoxus and echo RV collapse.
- Kussmaul sign — constrictive pericarditis and RCM (not tamponade — inflow limitation with dilated IVC).
- Square-root sign — dip-and-plateau on ventricular pressure tracing in constriction.
- TB pericarditis — commonest cause of constriction in India; treat with ATT plus early pericardiectomy for constriction.
- Purulent pericarditis — surgical drainage plus IV antibiotics; poor prognosis.
- Anthracycline cardiotoxicity — cumulative dose dependent, dilated CMP; monitor with echo and cardiac biomarkers.
- Cocaine cardiomyopathy — dilated with concurrent CAD acceleration.
- Post-radiation heart disease — pericarditis, restriction and premature CAD.
- Anakinra and rilonacept — colchicine-refractory recurrent pericarditis (RHAPSODY trial).
Recent updates and India context
- Mavacamten (2022) — first-in-class cardiac myosin inhibitor for symptomatic obstructive HCM; available in India via early-access/named-patient routes; reduces LVOT gradient and defers septal reduction therapy.
- Aficamten (SEQUOIA-HCM 2024) — second-generation myosin inhibitor with faster onset and shorter half-life; awaiting Indian regulatory clearance.
- ATTR amyloidosis awareness — routine PYP bone-tracer scanning in unexplained HFpEF with LVH has revealed a large hidden burden; tafamidis available in India via named-patient programmes; patisiran and vutrisiran (siRNA) for hereditary ATTR.
- RHAPSODY trial (2020) — rilonacept for recurrent pericarditis; anakinra also proven in AIRTRIP and IRAP studies.
- India ARVC registry — growing recognition in tertiary centres including AIIMS Delhi and PGIMER Chandigarh, driving family cascade screening.
- Post-COVID myopericarditis — reported after infection and in rare cases after mRNA vaccination; short course of NSAIDs and colchicine usually suffices.
- EMF at Sree Chitra Tirunal Institute (Trivandrum) — world reference centre for endomyocardectomy and AV valve repair.
- Rheumatic aetiology — India still contributes almost half the world's rheumatic heart disease; overlap with pericardial and myocardial disease in adolescents is a common clinical picture.
Frequently asked questions
How do you distinguish constrictive pericarditis from restrictive cardiomyopathy?
Both cause diastolic heart failure with preserved ejection fraction and biatrial enlargement, but constrictive pericarditis is potentially curable with pericardiectomy while RCM has a much poorer prognosis. Constriction shows a pericardial knock, Kussmaul sign, pericardial calcification on X-ray, a septal bounce on echo with respiratory interventricular dependence, and ventricular pressure equalisation on catheterisation. RCM has neither Kussmaul nor knock, shows severely elevated BNP, and demonstrates myocardial infiltration on cardiac MRI with late gadolinium enhancement typical of amyloid or sarcoid.
What is the classic murmur of hypertrophic obstructive cardiomyopathy?
HOCM produces a harsh crescendo-decrescendo systolic ejection murmur best heard at the left lower sternal border, radiating along it rather than to the carotids. The hallmark is dynamic behaviour — it increases with Valsalva strain, standing from squatting and after amyl nitrite (which reduce preload or afterload and worsen LVOT obstruction) and decreases with squatting, passive leg raise and handgrip. This is the opposite of aortic stenosis with the preload manoeuvres (Valsalva, standing, squatting, leg raise); handgrip softens both murmurs.
What is Beck's triad and does it appear in every cardiac tamponade?
Beck's triad is hypotension, muffled heart sounds and elevated jugular venous pressure — the classic teaching for tamponade. In practice it is present in fewer than a third of cases, especially in slow-accumulating chronic effusions. Pulsus paradoxus (an inspiratory drop in systolic BP over 10 mmHg) and echocardiographic diastolic right ventricular collapse plus a plethoric IVC are far more sensitive. Urgent pericardiocentesis under echo guidance via the subxiphoid approach is the treatment; do not wait for the full triad.
Why is endomyocardial fibrosis important in Indian cardiology?
Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy endemic to tropical regions including Kerala, coastal Karnataka and parts of Odisha, along with sub-Saharan Africa. Dense fibrosis of the RV or LV endocardium obliterates the ventricular apex, causing biventricular restrictive physiology, atrioventricular valve regurgitation and eosinophilia in the active phase. Endomyocardectomy plus valve repair or replacement at Sree Chitra Tirunal Institute (Trivandrum) is the world reference centre. Loffler endocarditis is the temperate-zone hypereosinophilic equivalent.
What are the causes of dilated cardiomyopathy an examiner will expect you to list?
The classic causes are idiopathic, familial or genetic (titin, lamin A/C, myosin heavy chain mutations), ischaemic cardiomyopathy (post-MI remodelling — strictly a DCM phenocopy excluded from the primary definition, but the commonest cause of a dilated hypokinetic LV overall), viral post-myocarditis (coxsackie B, parvovirus B19, HHV-6), alcohol, cocaine and methamphetamine, chemotherapy (anthracyclines, trastuzumab), peripartum, tachycardia-induced, endocrine (thyrotoxicosis, phaeochromocytoma, acromegaly), nutritional (thiamine, selenium, carnitine) and haemochromatosis. In India, ischaemic and idiopathic dominate; peripartum cardiomyopathy is high-yield in the Indian exam context.
This content is for educational purposes for NEET PG exam preparation. It is not a substitute for professional medical advice, diagnosis, or treatment. Clinical information has been reviewed by qualified medical professionals.
Written by: NEETPGAI Editorial Team
Reviewed by: NEETPGAI Medical Advisory Board
Last reviewed: September 2026
