Non-obstructive hypertrophic cardiomyopathy with mitral regurgitation requiring valve replacement

Non-obstructive hypertrophic cardiomyopathy (HCM) is rarely associated with mitral regurgitation severe enough to require valve replacement. A 39-year-old man, previously diagnosed as having non-obstructive HCM with mitral regurgitation, developed atrial fibrillation with tachycardia and congestive heart failure. Echocardiography and cardiac catheterization, including left ventriculography, documented an unusual type of non-obstructive HCM with severe mitral regurgitation. The patient underwent successful mitral valve replacement.