9 ASSESSMENT OF LEFT VENTRICULAR HYPERTROPHY IN HYPERTENSIVE ADOLESCENTS USING ECHO, ECG, AND X-RAY

Abstract

We performed chest x-rays, electrocardiograms (ECGs), and echocardiograms (ECHOs) on 35 hypertensive and 35 normotensive subjects 14-16 years of age who were matched for age, race, sex, and body size (ponderal index). All hypertensive patients had elevation of systolic and/or diastolic blood pressure at or above the 95th percentile for age on 3 consecutive examinations. No patient in either group showed cardiomegaly on chest x-ray. Five hypertensive patients (14%) and 7 control subjects (20%) had ECG criteria for LVH, indicating no significant difference between the groups. Analysis of ECHOs showed the mean left ventricular wall thickness (LVT) in hypertensives was 7.8mm±0.87 (SD), compared with 6.5mm±0.81 in the controls. Left ventricular mass indexed to body surface area (LVM/BSA) averaged 82±15 and 70±15 respectively. LVT was then also indexed to BSA and using our control data we defined the upper limits of normal in terms of the 90th percentile values: for LVT/BSA this was 0.470, and for LVM/BSA this was 100. Of hypertensive patients, 23% had LVT/BSA above the 90th percentile and 17% had LVM/BSA, above this level. For controls, only 3% had elevated LVT/BSA, and 6% had elevated LVM/BSA. These findings suggest that ECHO may be a more useful method than either chest x-ray or ECG to detect LVH in hypertensive adolescents.