Ventricular volume growth after cardiac transplantation in infants and children

Background. Intermediate-term survival after pediatric cardiac transplantation continues to improve. However, little is known about cardiac function and especially ventricular growth in young patients after cardiac transplantation. The purpose of this study was to evaluate serially the hemodynamics, left ventricular (LV) volume, and ventricular function after cardiac transplantation in infants and children. Methods and Results. Indications for cardiac transplantation were dilated cardiomyopathy (eight patients), hypoplastic left heart syndrome (six patients), and postoperative structural congenital heart disease (three patients). The age at time of transplant ranged from 7 days to 15 years (median, 3.5 years). The mean follow-up was 30.3 months (range, 13-46 months). Serial annual cardiac catheterizations were performed 1 year (17), 2 years (15), and 3 years (seven) after transplant. Measurements included right and left heart pressures, cardiac index, and LV volume and ejection fraction (Lange). Cumulative results (expressed as mean±SD) were pulmonary artery pressure, 14.9±3.2 mm Hg; LV end-diastolic pressure, 7.7±2.6 mm Hg; cardiac index, 3.5±0.52 l/min · m^-2; and pulmonary vascular resistance, 2.02±0.76 units/m². LV end-diastolic volume increased as patients grew, so that left ventricular end-diastolic volume remained 90±14% of that predicted for body surface area. The ejection fraction was 99±6% of that predicted. There was no evidence of chronic rejection by endomyocardial biopsy. No accelerated coronary artery atherosclerosis was identified. Conclusions. Serial studies in these young patients demonstrate normal hemodynamics and LV function after cardiac transplantation. Cardiac transplantation is associated with normal LV volume growth despite immunosuppression and denervation.