Diastolic function and tachycardia in hypertensive children

We investigated the prevalence and potential predictors of Doppler echocardiographic evidence of diastolic function in untreated hypertensive children. Doppler and M-mode echocardiographic: values from 42 children (mean age 13, range 5-17 years) from a pediatric hypertension clinic were retrospectively reviewed and compared to data from 39 age and gender matched normotensive children in a control group. Compared to the participants in the control group, hypertensive patients had increased mean body mass index (29 v 19 kg/M-2 P < .0001), peak mitral A velocity (57 v 42 cm/sec, P < .0001), isovolumic relaxation time (65 v 42 msec, P < .0001), resting heart rate (90 v 74 bpm, P < .0001), mitral E deceleration time (150 v 137 msec, P = .006), indexed left ventricular mass index (32 v 26 g/M-2.7, P < .0001), relative left ventricular wall thickness (0.32 v 0.29, P = .02), and decreased ratio of peak mitral E velocity/peak mitral A velocity (1.7 v 2.1, P = .0001). Mean age, height, mitral E velocity, mitral A deceleration time, fractional shortening, and indexed left ventricular diastolic dimension were similar in patients and control group children. In the hypertensive patients, multivariate analysis demonstrated that heart rate (P = 0008) and systolic blood pressure (P = .03) were significant predictors of peak A velocity. In addition, heart rate (P = .0003), body mass index (P = .04), and indexed left ventricular diastolic dimension (P = .04) predicted the ratio of peak E/peak A velocity. None of the measures of diastolic function correlated with left ventricular mass index or relative wall thickness. Furthermore, none of the analyzed variables predicted isovolumic relaxation time or mitral E deceleration time. We conclude that untreated hypertensive children have Doppler indices suggestive of impaired left ventricular relaxation. Resting heart rate was the strongest predictor of abnormal diastolic indices. (C) 1999 American Journal of Hypertension, Ltd.