Twenty-two heterotopic heart transplantations were performed, in 19 of which the evolution of the recipient heart was estimated. Within the first postoperative hours the recipient heart was often more effective than the donor heart. The discrepant rhythm between the 2 hearts did not result in any pathological findings. The increased pressures in the recipient's right heart always decreased, sometimes within several weeks. The left atrial volume was found to be reduced while left ventricular contraction was sometimes unchanged, sometimes improved and in a few cases showed definite improvement with a mean decrease of the ultra-sound diastolic diameter of 20 mm on echocardiography. The technique of heterotopic systems seems to be a useful indication for end-stage cardiomyopathies with pulmonary hypertension (class IV) which is generally considered a contraindication for orthotopic heart transplantation.