BP as a determinant of cardiac left ventricular muscle mass.

The relationship between casual BPs and measures of cardiac hypertrophy, derived from the ECG, has been described as fairly weak. In this study, ECG and echocardiographic measurements of left ventricular muscle mass were related to various measures of BP obtained during circadian ambulatory BP monitoring in 12 patients with hypertension. Casual BP did not correlate substantially with ECG voltages or with echocardiographic measurements of muscle mass. The correlations between whole-day, daytime, or nighttime BP averages and ECG voltages were not significant. However, echocardiographic left ventricular muscle mass correlated significantly with the averages of whole-day, daytime, and nighttime, and two-hour morning systolic pressures. The correlations between diastolic BP and left ventricular muscle mass were not significant. Therefore, serial BP measurements are required to evaluate the relationship between BP and left ventricular muscle mass as measured by the M-mode echocardiogram. The ECG is of little value in this relationship.