Abstract
A double diastolic murmur was heard in a patient with mitral stenosis, atrial fibrillation, and complete heart block. Echo-phonocardiographic examination showed two separate opening and closing movements of the mitral valve in the same long diastole. A clear time relation was observed between the valve closing movements and the separate diastolic murmurs, giving support to the theory that the backward motion of the mitral valve against the forward blood flow through the valve is responsible for the production of these murmurs.