Musical cooing murmurs in degenerated porcine valves--a report of three cases.

Three cases with typical cooing murmurs in degenerated porcine valves at mitral positions were studied. An echophonocardiogram disclosed that the origin of cooing murmur was due to cusp vibration with fixed cycle in frequency. Three failed xenografts were replaced with mechanical valves and the removed prostheses were examined. The first valve had a torn cusp, the second had a perforated cusp and the third had both a torn and perforated cusps. The failed leaflets were all pliable and not thickened in properties. These common findings are suspected to relate closely to the occurrence of a musical cooing murmur. Since all cases with cooing murmurs suddenly developed severe or progressive heart failure, we recommend prompt evaluation and reoperation when a cooing murmur appears in the patients with xenografts.