Dexamethasone given to premature infants and cardiac diastolic function in early childhood.

Abstract

To determine if dexamethasone given to premature infants with bronchopulmonary dysplasia would result in cardiac diastolic dysfunction in early childhood, a topic unstudied in humans. We compared seven children ages 3 to 8 years born at 26 weeks' gestation and given dexamethasone for bronchopulmonary dysplasia with eight gestation-matched and age-matched control children using echocardiography to assess measures of systolic and diastolic function. All dexamethasone patients had resolved hypertrophic cardiomyopathy. Dexamethasone patients had the same normal τ and isovolumic relaxation time (24.9 ± 2.8 and 54.6 ± 6.3 ms) as control patients (22.1 ± 3.0 and 48.8 ± 6.7 ms). Peak A velocities were the same in dexamethasone patients as in control patients (59.5 ± 15 versus 49.4 ± 5.8 cm/s, P = .10), resulting in unchanged E:A ratios (1.89 ± 0.57 versus 2.15 ± 0.43, P = .22). Peak E velocity and E-wave deceleration times were not different. We found no significant differences in measures of systolic function (heart rate-corrected velocity of circumferential fiber shortening, wall stress, and ejection fraction). Left ventricular mass was the same between the groups confirming resolution of hypertrophic cardiomyopathy. These data are consistent with normal myocardial relaxation, suggesting that long-term diastolic function is reassuringly normal in children who received dexamethasone as premature infants with resolution of hypertrophic cardiomyopathy.