RACIAL-DIFFERENCES IN CARDIAC STRUCTURE AND FUNCTION IN ESSENTIAL-HYPERTENSION

Objective-To assess racial differences in cardiac structure and functi on in patients presenting with previously untreated hypertension. Desi gn-Untreated black patients with hypertension were compared with untre ated white patients matched for age and sex. Both groups had similar b ody mass indices, blood pressures, and reported duration of hypertensi on. Setting-Cardiovascular risk factor clinic for outpatients. Subject s-36 men and 22 women with untreated essential hypertension. Main outc ome measures-Variables of heart structure and function on cross sectio nal and Doppler echocardiography. Results-The black patients had a sig nificantly greater interventricular septal thickness (mean 1.23 (95% c onfidence interval 1.14 to 1.33) v 1.09 (1.02 to 1.16) cm; P = 0 02) a nd posterior wall thickness (mean 1.14 (1.07 to 1.22) v 0.96 (0.88 to 1.03) cm; P - 0.001) than the white patients, although left ventricula r internal diameter was not significantly different (mean 4.90 (4.68 t o 5.12) v 4.82 (4.64 to 5.01) cm; P = 0.59). This resulted in a signif icantly greater left ventricular mass index (mean 151 (137 to 164) v 1 20 (107 to 133) g/m(2); P = 0.001) and relative wall thickness (mean 0 .47 (0.43 to 0.51)v 0.40 (0.37 to 0.42) cm; P = 004) in the black pati ents. Comparison of Doppler measures of left ventricular diastolic fun ction showed a significantly longer isovolumic relaxation time in blac k patients (mean 107 (98 to 116) v 92 (83to 101) ms; P = 0 02) compare d with white patients, although peak early to atrial filling ratios we re similar in both groups (mean 1.14 (0.95 to 1.32) v 1.04 (0.94 to 1. 15); P = 0.37). Conclusion-Among previously untreated hypertensive pat ients, black subjects compared with white subjects have significantly higher left ventricular mass index and relative wall thickness, as wel l as more impairment of left ventricular function during diastole.