Early effects of mild hypertension on the heart. A longitudinal study.

SUMMARY M-mode echocardiograms were recorded twice, 1 year apart, in a group of 20 men and four women with mild hypertension (mean diastoiic (D) BP of 90 to 104 mm Hg) to assess the cardiac response to this modest increase in pressure load and to study the evolution of any changes at entry in the absence of pharmacological therapy. Results were compared with those collected on normotensive (N) subjects (DBP 80 mm Hg or less) matched at entry for age, sex, and lerel of activity. Analysis of covariance controlling for body surface area or change in body surface area was used to assess statistical significance of differences between groups; results were expressed as means±standard error of mean. At entry, the hypertensive (H) group had a significantly smaller left ventricular (LV) internal diameter in diastole (46.0±1.4 mm vs 49.9±0.9 mm, p < 0.003) and in systole (28.4±1.0 mm vs 31.5±1.0 mm, p < 0.001), and a significantly larger left atrial dimension (36.1±0.9 mm vs 33.0±0.9 mm, p < 0.05) compared with values in N subjects. There was no significant difference in the thickness of the LV posterior wall or interventricular septum in either systole or diastole, or in the fractional fiber shortening between the N and H subjects. One year later, in the hypertensive group only, there was a significant increase in the systolic dimension of the left ventricle (p < 0.05) and a reduction, although not statistically significant, in the percent fractional fiber shortening. These findings suggest that in early stages of hypertension before LV hypertrophy can be detected by echocardiography there is a reduction in LV compliance, with subsequent gradual change in contractile function. (Hypertension 3 (suppl II): II-187-H-190, 1981)