Contrast in cardiac anatomy and function between black and white patients with hypertension.

Overview

To determine whether cardiac findings differ between blacks and whites with essential hypertension, members of a well-defined working population in New York City were examined. Hypertensives had diastolic blood pressure ≤95, or systolic blood pressure ≤160 mmHg, or both, sustained on three occasions over three weeks. Normotensives were selected to reflect the age, sex, and race distribution of the total working population. Of 207 employees, 75 hypertensives (40 percent blacks) and 132 normotensives (53 percent blacks) under-went M-mode echocardiography. Left ventricular (LV) measurements and simultaneous blood pressure by mercury manometer were used to calculate LV mass index (LVMI), relative wall thickness (RWTd), cardiac output (CO) and total peripheral resistance (TPR). There were no differences in any variable between black and white normotensives. Black and white hypertensives were similar in age (52 ± 10 and 54 ± 12 yr, respectively) and blood pressure (151/100 ± 15/11 and 153/99 ± 18/8 mmHg). Black hypertensives had significantly higher TPR (1.80 ± 0.74 vs 1.43 ± 0.46, P<.01), lower CO (6.0 ± 2.5 vs 7.2 ± 2.4 L/min, P<.01), and higher RWTd (0.43 ± 0.11 vs 0.37 ± 0.07, P<.05) than white hypertensives. Race, per se, cannot explain these differences since they did not occur among normotensives. Rather, these findings may reflect a differing patho-physiology of hypertension in blacks and whites with similar blood pressure elevation.