A 46-year-old man has progressive right-sided heart failure with raised JVP showing Kussmaul sign and a pericardial knock. Echo shows a septal bounce and restrictive filling (E/A greater than 2). Tissue Doppler shows mitral annular e-prime velocity of 4 cm/s, and NT-proBNP is markedly elevated. Which single finding argues for restrictive cardiomyopathy rather than constrictive pericarditis?
- A Kussmaul sign
- B Reduced mitral annular e-prime velocity ✓
- C Septal bounce
- D Pericardial knock
Correct answer: B. Reduced mitral annular e-prime velocity
Explanation
In constrictive pericarditis the myocardium is intrinsically normal, so longitudinal relaxation measured by mitral annular e-prime is preserved, typically above 7 to 8 cm/s. In restrictive cardiomyopathy the disease lies within the myocardium itself, so e-prime is reduced. Kussmaul sign, the pericardial knock, and the septal bounce reflect pericardial constraint and are seen in constriction, so they cannot separate the two entities here.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.