Heart Failure & Cardiomyopathy: Step 1 review notes and self-test
Notes for the Heart Failure & Cardiomyopathy rapid review: the clue that separates each of its 7 confusion pairs, with timestamps and a self-test.
October 21, 2026
This video covers heart failure and cardiomyopathy confusion pairs, including dilated, hypertrophic, restrictive, and pericardial filling disorders. Watch the video, then use these notes to test whether you can identify the separating clue.
Dilated cardiomyopathy vs Hypertrophic and restrictive cardiomyopathy
Dilated cardiomyopathy has dilated chambers, systolic dysfunction, and reduced ejection fraction, while hypertrophic and restrictive cardiomyopathy primarily cause diastolic filling or obstruction patterns. HCM has asymmetric septal hypertrophy with dynamic obstruction, while restrictive cardiomyopathy has stiff ventricular filling. Do not rely on wall thickness alone. Identify chamber size, ejection fraction, and diastolic filling before you name the type.
Dilated cardiomyopathy vs Hypertrophic and restrictive cardiomyopathy Dilated is systolic low EF; hypertrophic and restrictive are primarily diastolic filling/obstruction patterns. Open the comparison and video →Left-sided heart failure vs Right-sided heart failure
Left-sided heart failure causes pulmonary congestion with dyspnea, orthopnea, crackles, and pulmonary edema, while right-sided heart failure causes systemic venous congestion with JVD, hepatomegaly, ascites, and peripheral edema. Dyspnea can occur in both because right-sided failure commonly follows left-sided failure. Look for whether the congestion is in the lungs or systemic veins, while remembering that left-sided failure is the most common cause of right-sided failure.
Left-sided heart failure vs Right-sided heart failure Left-sided failure: pulmonary congestion (dyspnea, crackles, S3); right-sided failure: systemic congestion (JVD, edema, ascites). Open the comparison and video →Cor pulmonale vs Left heart failure
Cor pulmonale starts with primary lung or pulmonary vascular disease that causes pulmonary hypertension and right ventricular hypertrophy or failure, while left heart failure starts with LV dysfunction and causes pulmonary venous congestion. Right-sided edema does not automatically mean cor pulmonale because LV failure is the most common cause of right-sided failure overall. When you see RV failure, identify whether lung disease or left heart disease raised RV afterload.
Cor pulmonale vs Left heart failure Cor pulmonale starts in lung/pulmonary vessels and fails the RV; left HF starts in the LV and congests the lungs. Open the comparison and video →Restrictive cardiomyopathy vs Constrictive pericarditis
Restrictive cardiomyopathy is stiff myocardium, while constrictive pericarditis is a rigid pericardium with exaggerated ventricular interdependence. Both can cause diastolic failure with preserved ejection fraction, biatrial enlargement, Kussmaul sign, and right-sided congestion. Pericardial calcification or thickening above 3 mm, a pericardial knock, and respiratory variation in ventricular inflow point to constriction, while biventricular wall thickening with a normal pericardium points to restriction. Amyloid can show low-voltage ECG despite thick walls and apical sparing on strain imaging.
Restrictive cardiomyopathy vs Constrictive pericarditis Restrictive is stiff myocardium; constrictive is stiff pericardium with exaggerated ventricular interdependence. Open the comparison and video →Constrictive pericarditis vs Cardiac tamponade
Constrictive pericarditis is a chronic rigid pericardial shell with Kussmaul sign and a pericardial knock, while cardiac tamponade is pressurized pericardial fluid with hypotension, pulsus paradoxus, and possible electrical alternans. Both impair ventricular filling and can equalize diastolic pressures across all four chambers. Kussmaul sign points to constriction, while pulsus paradoxus over 10 mmHg points to tamponade. On echo, effusion with right atrial and right ventricular diastolic collapse points to tamponade, while pericardial thickening or calcification with septal bounce and respirophasic septal shift points to constriction.
Constrictive pericarditis vs Cardiac tamponade Constrictive pericarditis is chronic rigid shell with Kussmaul/knock; tamponade is pressurized fluid with shock/pulsus paradoxus. Open the comparison and video →Cardiac tamponade vs Tension pneumothorax
Cardiac tamponade has muffled heart sounds and pericardial effusion, while tension pneumothorax has absent unilateral breath sounds with hyperresonance. Both can cause obstructive shock with hypotension, JVD, and pulsus paradoxus. Muffled heart sounds with bilateral breath sounds point to tamponade, while absent unilateral breath sounds with hyperresonance and tracheal deviation away from the affected side point to tension pneumothorax. Listen to the heart and lungs before you choose the emergency procedure.
Cardiac tamponade vs Tension pneumothorax Tamponade is muffled heart sounds and effusion; tension pneumothorax is absent unilateral breath sounds with hyperresonance. Open the comparison and video →Septic shock vs Cardiogenic shock
Septic shock is infection-driven vasodilation with low SVR, high or normal cardiac output early, and low-to-normal PCWP, while cardiogenic shock is pump failure with high SVR, low cardiac output, and high PCWP. Do not use skin temperature alone because late septic shock can cause cold, mottled extremities that resemble cardiogenic shock. If Swan-Ganz measurements are unavailable, use early bedside echo, lactate, and an infection workup to distinguish them.
Septic shock vs Cardiogenic shock Septic shock is low-SVR vasodilation; cardiogenic shock is pump failure with high filling pressures. Open the comparison and video →Quick self-test
Name the diagnosis from the clue, then tap to check.
Pericardial fluid under pressure causing hypotension, JVD, muffled heart sounds, pulsus paradoxus, and possible electrical alternans.
Cardiac tamponade · Constrictive pericarditis vs Cardiac tamponade
LV systolic or diastolic dysfunction causing pulmonary venous congestion, orthopnea, crackles, pulmonary edema, and often secondary RV strain later.
Left heart failure · Cor pulmonale vs Left heart failure
Diastolic dysfunction from rigid pericardium, often with pericardial calcification or knock.
Constrictive pericarditis · Restrictive cardiomyopathy vs Constrictive pericarditis
Diastolic dysfunction from stiff myocardium, often due to infiltrative disease.
Restrictive cardiomyopathy · Restrictive cardiomyopathy vs Constrictive pericarditis
Chronic rigid pericardium with right-sided congestion, Kussmaul sign, pericardial knock, and preserved systolic function.
Constrictive pericarditis · Constrictive pericarditis vs Cardiac tamponade
Dyspnea, orthopnea, crackles, pulmonary edema, and reduced forward output.
Left-sided heart failure · Left-sided heart failure vs Right-sided heart failure
Right ventricular hypertrophy/failure from primary lung disease or pulmonary vascular disease causing pulmonary hypertension.
Cor pulmonale · Cor pulmonale vs Left heart failure
Hypotension, JVD, muffled heart sounds, pulsus paradoxus, and electrical alternans.
Cardiac tamponade · Cardiac tamponade vs Tension pneumothorax
Keep going
Every pair in this review has a free page in the library with a side-by-side comparison and a practice question. Work through the ones you missed in the self-test first.