Restrictive cardiomyopathy is characterized by which of the following?

• A. Systolic dysfunction with reduced EF
• B. LV dilation with systolic failure
• C. Diastolic dysfunction with failure to expand, LV thickness normal; causes include fibrosis, amyloidosis, sarcoidosis
• D. Pericardial effusion

Answer: (C)

Restrictive cardiomyopathy is defined by diastolic dysfunction from a stiff ventricle that cannot expand properly during filling, while systolic function remains preserved. The ventricle’s noncompliance leads to high filling pressures and heart failure symptoms despite a normal or near-normal ejection fraction. The description “diastolic dysfunction with failure to expand, LV thickness normal; causes include fibrosis, amyloidosis, sarcoidosis” captures this pattern and the common etiologies, including infiltrative and fibrotic processes that stiffen the ventricle without causing primary dilation or systolic failure.

The other options describe different problems: reduced systolic function points to dilated cardiomyopathy; LV dilation with systolic failure is also characteristic of systolic-dominant disease; a pericardial effusion involves the pericardial space rather than the myocardium itself and can lead to different hemodynamics (and, in a subset, constrictive physiology that mimics restrictive signs but is not restrictive cardiomyopathy).