Phonocardiographic recording of heterotopic cardiac graft function in the rat. I. Diagnosis of rejection.
Daily simultaneous recordings of an electrocardiogram and an external thorax phonocardiogram and abdominal phonocardiogram were obtained in 24 rats with abdominal heart grafts so that rejection could be studied. The sounds recorded above the heterotopic heart are the result of a pressure differential between host and graft ventricle competing with one another. As soon as the contractility of the graft ventricle decreases below the contractility of the host ventricle, characteristic and specific changes occur in the abdominal phonocardiogram: the amplitude of the first sound becomes smaller while the timing of the second heart sound (aortic valve closure) is subsequently controlled by the host ventricle. These observations coincide with clinical and histological symptoms of rejection and are, therefore, of diagnostic value. In addition, a rough quantitative record of graft function is obtained by abdominal phonocardiography using the host's own cardiac function as a reference parameter.
D000818:Animals; D004562:Electrocardiography; D006084:Graft Rejection; D016027:Heart Transplantation; D008297:Male; D009206:Myocardium / Q000473:pathology; D010701:Phonocardiography; D051381:Rats; D011914:Rats, Inbred BN; D011917:Rats, Inbred Lew; D014184:Transplantation, Homologous