Evaluation of the inotropic function at rest and the effect of enoximone in heart transplanted recipients. Assessment by left ventricular endsystolic pressure volume relationship.

Denervation of the heart involves an alteration (density, distribution of beta 1-beta 2-types) of beta-adrenoceptors in long-term follow-up. To elucidate the influence of these changes on left ventricular contractility and to provide an effective alternative treatment to re-transplantation in cases of chronic rejection (coronary vasculopathy-CVP, unspecific myocardial allograft failure-UMAF) a clinical study on 19 male transplant recipients after orthotopic heart transplantation without CVP and UMAF in the non-rejecting state was undertaken. Six male patients served as a control group to compare the systolic function at rest. Left ventricular end-systolic pressure-volume relationships (ESPVR) (k-slope) were registered and computer measured using a conductance catheter-technique under conditions of a transiently occluded vena cava and at a fixed heart rate (atrial pacing) in all patients (n = 25). In the transplanted patient group the acute response of enoximone (0.75 mg/kg) administered intravenously was recorded. The position of the ESPVR in the transplanted hearts were not different as compared to the data obtained from the non-transplanted hearts at rest. The k-slope increased from the baseline data after the acute infusion of enoximone in the transplanted hearts. The dosage of enoximone used produced a significant leftward shift in the ESPVR in most patients (89%). In addition, 42% of the patients showed an insignificant drop in left ventricular systolic pressure. Thus, the baseline contractile characteristics of the heart transplant recipients without chronic rejection and in the non-rejecting state is not obviously different from those in non-transplanted patients at rest independent of the time since operation.(ABSTRACT TRUNCATED AT 250 WORDS)