[Cardiac transplantation: noninvasive detection of rejection by echocardiography]

The main objective of follow-up of cardiac transplant patients is early recognition of acute rejection of the allogenic myocardium. Two patients followed up by the usual protocol also underwent routine M-mode and 2D echocardiography. The data was digitalized and memorized to allow systematic study of the pericardial and cardiac structures, and a comparison of their evolution. Acute rejection was associated with an increase in the acoustic density of the myocardium, especially of the interventricular septum, and an increase in myocardial mass as calculated from M-mode data; an increase of 5 p. 100 of this parameter with respect to an average reference value was judged to be significant. Comparisons were made with electrocardiographic data, especially with an index of voltage. The variability of this index which may be unrelated to rejection was apparent; in addition, there was an interval of about 5 days between the echocardiographic changes and the recording of significant reductions of the electrocardiographic index. Previously reported histological changes explain the precocity and reliability of the echocardiographic results obtained by a non-invasive and reproducible method.