INFANT AND DONOR ORGAN GROWTH AFTER HEART-TRANSPLANTATION IN NEONATESWITH HYPOPLASTIC LEFT-HEART SYNDROME

Background: There is little published data regarding somatic growth an d changes in allograft size after heart transplantation in infants wit h hypoplastic left heart syndrome. Methods: We evaluated the somatic g rowth of 26 infants with hypoplastic left heart syndrome who underwent heart transplantation over a 5-year period and measured changes in le ft ventricular dimensions in 22 of those infants. Age at transplantati on was 27 +/- 17 days (mean +/- standard deviation), and the follow-up period was 43 +/- 14 months. Growth and echocardiographic data were c onverted to standard deviation (Z) scores for comparison with normal p opulations. Results: Height and weight were always within normal limit s (two standard deviations), with a trend toward smaller size througho ut the follow-up period. The somatic growth of infants on low-dose mai ntenance steroids was not significantly different from that of infants withdrawn from chronic steroid regimens. Initial left ventricular pos terior wall and septal dimensions were greater than two standard devia tions (+4.3 and +6, respectively), probably the result of routine use of oversized donors, but the dimensions decreased to within the normal range during the first year. They then remained within normal limits during follow-up. With one exception at 2 years after transplantation, left ventricular diastolic dimensions were always within two standard deviations of the mean. Left ventricular dimensions of patients with hypertension, rejection, or acute graft failure were not significantly different from patients without these complications. Conclusions: Neo nates with hypoplastic left heart syndrome who undergo heart transplan tation can be expected to have somatic growth within normal limits. Ho wever, the trend toward growth retardation is worrisome. Left ventricu lar wall dimensions adjust to smaller recipient size during the first year after transplantation and then remain appropriate for the recipie nt's size over time.