Doppler evaluation of left ventricular diastolic filling in children with systemic hypertension

Abstract

To assess left ventricular (LV) diastolic function in children with systemic hypertension, 11 patients with hypertension (mean blood pressure 99 mm Hg) and 7 normal patients (mean blood pressure 78 mm Hg) underwent M-mode echocardiography and pulsed Doppler examination of the LV inflow. From a digitized trace of the LV endocardium and a simultaneous phonocardiogram, echocardiographic diastolic time intervals, peak rate of increase in LV dimension ( dD dt ), and dD dt normalized for LV end-diastolic dimension ( dD dt ) were measured. Doppler diastolic time intervals, peak velocities at rapid filling (E velocity) and atrial contraction (A velocity), and the ratio of E and A velocities were measured. The following areas under the Doppler curve and their percent of the total area were determined: first 33% of diastole (0.33 area), first 50% of diastole, triangle under the A velocity (A area), and the triangle under the E velocity (E area). The A velocity (patients with hypertension = 0.68 ± 0.11 m/s, normal subjects = 0.49 ± 0.08 m/s), the 0.33 area/total area (patients with hypertension = 0.49 ± 0.09, normal subjects = 0.58 ± 0.08), the A area (patients with hypertension = 0.17 ± 0.05, normal subjects = 0.12 ± 0.03), and the A area/total area (patients with hypertension = 0.30 ± 0.11, normal subjects = 0.20 ± 0.07) were significantly different between groups (p < 0.05). M-mode and Doppler time intervals, dt D , E velocity, and the remaining Doppler areas were not significantly different between groups. The normal subjects and patients with hypertension did not differ significantly in echocardiographic LV size and thickness or in percent shortening fraction. This study shows that abnormal patterns of LV diastolic filling occur in children with mild systemic hypertension. These diastolic abnormalities are detectable by mitral valve Doppler ultrasound examination when standard M-mode echocardiographic indexes of diastolic function are still normal and before the development of systolic function abnormalities or LV hypertrophy on the M-mode echocardiogram.