Hypertension, hypertrophy, and the occurrence of cardiovascular disease

Abstract

Hypertension is a major contributor to cardiovascular morbidity and mortality, increasing risk threefold. It predisposes to every clinical manifestation of coronary heart disease, now the most common and lethal outcome. It is as relevant a risk factor in the elderly as in the young. Risk is proportional to the degree of blood pressure elevation without a discernible critical value. Cardiovascular sequelae do not derive chiefly from the diastolic component, and isolated systolic hypertension confers increased risk at all ages. Hypertension tends to cluster with other cardiovascular risk factors, which must be taken into account in evaluating the risk and in choosing treatment. The excess cardiovascular risk in hypertension is concentrated in those with an increased total/high density lipoprotein cholesterol ratio, glucose intolerance, cigarette smoking, elevated fibrinogen, and electrocardiogram abnormalities. Left ventricular hypertrophy (LVH) is a common feature of hypertension and an ominous harbinger of cardiovascular sequellae. Electrocardiographic evidence of LVH, when manifested by repolarization abnormalities and voltage elevations, is particularly hazardous, reflecting not only anatomical hypertrophy but also ischemia. Electrocardiogram-LVH adds to cardiovascular risk associated with X ray or echocardiographic evidence of anatomical LVH. Because of a tendency to ventricular ectopy, LVH is associated with increased risk of sudden death. Electrocardiogram-LVH can be corrected or avoided by control of hypertension and weight reduction. The efficacy of correcting LVH remains to be demonstrated but benefits seem likely.