Heart Sounds in Patients with Homograft Replacement of the Mitral Valve

Phonocardiographic, hemodynamic, angiographic, and cardiac echographic studies have been performed on 11 patients whose diseased mitral valves have been replaced by a supported aortic valve homograft. The chordae tendineae and papillary muscles were removed in all patients during the operation. Apical first heart sounds of normal intensity were present in all patients after surgery. Nine patients exhibited splitting of the first sound. The initial component occurred when bulging of the homograft leaflets into the atrium was suddenly checked after the onset of ventricular systole. The second component occurred at the onset of rapid annular motion toward the base. Both sounds thus appear to originate in the homograft valve. Four patients had third heart sounds of left ventricular origin. The homograft leaflets were open and demonstrated no abrupt motion at the time of the third sound. It is evident that the third heart sound may occur in the absence of chordae tendineae and papillary muscles.