Diastolic mitral regurgitation in patients with hypertrophic cardiomyopathy.

An analysis of the left ventricular angiograms of 31 patients with hypertrophic cardiomyopathy revealed diastolic mitral regurgitation in 4, a prevalence of 12.9%. The clinical, echocardiographic, angiographic, and hemodynamic data of these patients were reviewed. Diastolic mitral regurgitation could not be attributed to arrhythmia, PR interval prolongation, atrioventricular dissociation, aortic insufficiency, or aortic stenosis. Reduced left ventricular compliance was evidenced by elevated end-diastolic pressure following angiography and reduced diastolic E-F slope on echocardiography. It is speculated that the rapid inflow of blood into a poorly compliant ventricle established a turbulent flow pattern that resulted in the "floating" of blood back into the left atrium.