Abnormal pulmonary artery pressure profile after cardiac transplantation: an exercise Doppler echocardiographic study

This study was designed to test the hypothesis that pulmonary artery pressure at rest and during exercise differs between patients with a transplanted heart and normal subjects and to determine the mechanisms responsible for the difference. Twenty-one patients who had undergone heart transplantation 1.5 to 27 months earlier without current evidence of acute cardiac rejection and 25 normal subjects were studied by exercise Doppler echocardiography. Systolic pulmonary artery pressure was higher at baseline in heart transplant patients than in normal subjects, at 31.6 +/- 9 mm Hg (mean +/- SD) versus 22.5 +/- 4, respectively (p = 0.0001). The increase in systolic pulmonary artery pressure with exercise was 1.4 times higher in heart transplant patients and correlated with pretransplantation pulmonary vascular resistances (r = 0.55; p = 0.01). In contrast, cardiac index at baseline or during exercise did not differ between the two groups. Diastolic parameters and ejection fraction at baseline or during exercise did not correlate with systolic pulmonary artery pressure. In conclusion, Doppler exercise echocardiography offers an alternative, safe method hemodynamic study of the transplanted heart. Although an abnormal increase in left ventricular filling pressure with exercise has been well documented, further studies are needed to investigate and characterize potential abnormalities in pulmonary vascular tone in the transplanted heart.