Diastolic rumbles in normally functioning porcine mitral valves.

Fourteen of 22 patients (64%) with normally functioning porcine prosthetic valves in the mitral position had apical diastolic rumbles on phonocardiogram and by auscultation. Six (27%) had opening snaps. Factors necessary for the production of a diastolic rumble appear to include central flow, a flexible stent, and the presence of biologic material. Clinicians should be aware that diastolic murmurs and snaps occur in the normally functioning porcine valve.