[Noninvasive diagnosis of myocardial rejection using echocardiography]

The potential of echocardiography in evaluating myocardial rejection was determined in 56 patients (8 females) following orthotopic heart transplantation. The patients' average age was 42.3 (range 18-67) years. Endomyocardial biopsy was used as the reference method. The study included a total of 254 results of biopsy: 137 specimens were free of any signs of rejection while 51 showed incipient rejection and mild rejection was found in 54 specimens. Moderate rejection was detected in 12 specimens; severe rejection was not present in any case. Echocardiography was used to determine ventricular size, wall thickness, left ventricular function, pericardial effusion, mitral and tricuspid flow and isovolumic relaxation time. Rejection has been found to be associated with ventricular wall thickening; the appearance of or an increase in pericardial effusion seems to be a relatively specific feature (a very low-sensitivity marker though); change in isovolumic relaxation time is believed to be the most sensitive marker. No relation between rejection and mitral and tricuspid flow was demonstrated. Echocardiography may alert the cardiologist to a rejection episode; isovolumic relaxation time and its alterations are the most informative features in this respect. The method may help postpone the intervals of biopsy which, however, must be performed on the slightest suspicion of rejection. Still, it cannot be regarded as a replacement for endomyocardial biopsy at the moment.