Constrictive pericarditis vs Cardiac tamponade
How to tell Constrictive pericarditis and Cardiac tamponade apart when a board question makes them look alike.
Constrictive pericarditis is chronic rigid shell with Kussmaul/knock; tamponade is pressurized fluid with shock/pulsus paradoxus.
Side by side
Chronic rigid pericardium with right-sided congestion, Kussmaul sign, pericardial knock, and preserved systolic function.
Pericardial fluid under pressure causing hypotension, JVD, muffled heart sounds, pulsus paradoxus, and possible electrical alternans.
Scarred pericardium prevents normal diastolic expansion and dissociates intrathoracic from intracardiac pressure transmission.
Rising intrapericardial pressure compresses chambers and limits diastolic filling acutely.
TB/radiation/cardiac surgery history, pericardial calcification, Kussmaul sign, or knock points constriction.
Rapid effusion, Beck triad, pulsus paradoxus, right atrial/RV diastolic collapse, or electrical alternans points tamponade.
The trap
Both impair ventricular filling and equalize diastolic pressures across all four chambers, so right heart catheterization shows similar patterns. The Kussmaul sign (paradoxical rise in JVP with inspiration) is present in constriction and absent in tamponade. Pulsus paradoxus over 10 mmHg is the hallmark of tamponade and is usually absent or mild in constriction. Echo decides: tamponade shows pericardial effusion with RV and RA diastolic collapse and over 25 percent respiratory variation in mitral inflow; constriction shows pericardial thickening or calcification with septal bounce and respirophasic septal shift.
Watch it explained
The repair move
For pericardial filling problems, decide pressurized fluid versus rigid scar in three steps: (1) check pulsus paradoxus (over 10 mmHg suggests tamponade); (2) check Kussmaul sign (present suggests constriction); (3) order echo (effusion with chamber collapse equals tamponade and needs pericardiocentesis; thickened or calcified pericardium with respirophasic septal shift equals constriction and may need pericardiectomy).
Try a free question
CoreA patient with prior tuberculosis has chronic edema, ascites, JVD that rises with inspiration, and a pericardial knock. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Constrictive pericarditis. Constrictive pericarditis is chronic rigid pericardial constraint with right-sided congestion, Kussmaul sign, and pericardial knock.
Why the other choices are tempting
- B. Cardiac tamponade is acute/subacute pericardial pressure with hypotension, muffled heart sounds, JVD, and pulsus paradoxus.
- C. Dilated cardiomyopathy causes systolic dysfunction with chamber dilation.
- D. Aortic regurgitation causes wide pulse pressure and early diastolic murmur.
- E. PE causes acute dyspnea, pleuritic pain, and RV strain rather than chronic pericardial knock.
Flashcards
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What is the fastest separator for Constrictive pericarditis vs Cardiac tamponade?
Constrictive pericarditis is chronic rigid shell with Kussmaul/knock; tamponade is pressurized fluid with shock/pulsus paradoxus.
What clue should make you choose Constrictive pericarditis?
Chronic rigid pericardium with right-sided congestion, Kussmaul sign, pericardial knock, and preserved systolic function.
Quick answers
What is the fastest way to tell Constrictive pericarditis from Cardiac tamponade?
Constrictive pericarditis is chronic rigid shell with Kussmaul/knock; tamponade is pressurized fluid with shock/pulsus paradoxus.
What is the key clue for Constrictive pericarditis?
Chronic rigid pericardium with right-sided congestion, Kussmaul sign, pericardial knock, and preserved systolic function.
What is the key clue for Cardiac tamponade?
Pericardial fluid under pressure causing hypotension, JVD, muffled heart sounds, pulsus paradoxus, and possible electrical alternans.
What is the common trap with Constrictive pericarditis vs Cardiac tamponade?
Both impair ventricular filling and equalize diastolic pressures across all four chambers, so right heart catheterization shows similar patterns. The Kussmaul sign (paradoxical rise in JVP with inspiration) is present in constriction and absent in tamponade. Pulsus paradoxus over 10 mmHg is the hallmark of tamponade and is usually absent or mild in constriction. Echo decides: tamponade shows pericardial effusion with RV and RA diastolic collapse and over 25 percent respiratory variation in mitral inflow; constriction shows pericardial thickening or calcification with septal bounce and respirophasic septal shift.