[Dysfunction of Carpentier-Edwards porcine mitral bioprosthesis causing a musical systolic murmur: a report of two cases].

Two patients with disruption of Carpentier-Edwards porcine mitral bioprosthesis presenting with a musical systolic murmur were reported. The two patients noted sudden development of a loud musical murmur 4 (Case 1) and 6.5 (Case 2) years after surgery. Case 1 had associated heart failure. Phonocardiogram disclosed a loud musical systolic murmur with regular vibrations at 230-240 Hz in Case 1, and 250-260 Hz in Case 2. In Case 1, echocardiography demonstrated fine fluttering of the porcine mitral valve at the same frequency as the murmur. Doppler echocardiography revealed characteristic Doppler signals from the porcine valves at a frequency of 250-300 Hz with several harmonics above and below the baseline. In addition, in Case 2, similar Doppler signals were obtained from the aortic walls, ventricular septum and posterior wall of the left ventricle. In both cases, left ventriculograms demonstrated grade 3 mitral regurgitation without paravalvular leakage, and at surgery, the porcine bioprosthesis showed a tear in one of markedly thinned cusps, without evidence of calcification. It was considered that a torn cusp was the source of the murmur, and this, in association with the resonance of the entire heart, produced the loud musical murmur. Thus, a musical systolic murmur is suggested to be one of important signs of dysfunction of porcine bioprosthesis.