[Central and peripheral circulation in patients after orthotopic transplantation of the heart]

Heart transplantation in human medicine is a unique model which makes it possible to study circulatory changes in complete denervation of the heart. The authors examined repeatedly the central and peripheral haemodynamics after orthotopic heart transplantation (OTS) in 11 patients (11 males, 1 female; mean age 44 +/- 4 years) following an interval of three months to four years after the operation. The values of central haemodynamics at rest varied in the majority within the normal range. After a load, in patients after OTS the heart rate rises only slowly. There is an abnormal rise of the filling pressure in both ventricles which leads also to an abnormal rise of pressure in the pulmonary artery with regard to flow. The cardiac output and stroke volume increase adequately. The peripheral circulation is characterized by persisting vasoconstriction in the area of resistant vessels and the venous circulation. The above changes reflect the different regulation of cardiac output after complete denervation of the heart by transplantation when the magnitude of the cardiac output is controlled mostly by the Frank-Starling mechanism. Changes of the tonus of the peripheral circulation contribute under these conditions to the maintenance of an adequate output.