The aim of the study was to analyse trends of hemodynamic parameters recorded during exercise stress test in patients after orthotopic heart transplantation. Twenty-one subjects aged 19-62 (x=44) were examined. They were divided into two groups: Group I consisted of 11 patients 6 to 12 (x=10) months after heart transplantation without clinical signs of acute rejection, treated with triple drug immunosuppression. Group II (control) included 10 subjects without signs of circulatory disease, with negative ECG exercise test. Heart rate (HR), cardiac index (CI), stroke index (SI), end-diastolic index (EDI) and left ventricular ejection fraction (EF) were monitored with the use of impedance reography (AVL 2001 system). The bicycle exercise test was performed in supine position with work load starting from 25W increased by 25W every 3 minutes. ECG was monitored continuously. Blood pressure (BP) was recorded noninvasively at every stage. Standard criteria of test termination were used. At rest heart rate (104 v. 65 p<0.0001), systolic (146 v. 121 p<0.005) and diastolic (99 v. 75 p<0.001) blood pressure and double product (15236 v. 7902 p<0.00001) were significantly higher in group I whereas these parameters did not differ in both groups at peak exercise. Increase of SI (20.5 v -1.5 p<0.05) and EDI (23.1 v. -8.4 p<0.05) during exercise in group I was significantly higher than in control group, while increase of CI and EF was similar between groups. HR rise was lower in group I (31 vs. 64 bpm.). Conclusions: 1. An increase of cardiac output induced by exercise in patients after orthotopic heart transplantation is caused mainly by an increase of the end-diastolic volume and stroke volume. 2. Impedance reography is a feasible method for non invasive assessment of left ventricle function in patients after heart transplantation.

Keywords: Heart Transplantation, haemodynamic monitoring, Physical effort, impedance reography