Relation of circulating blood volume to left ventricular geometry in essential hypertension

To investigate whether circulating blood volume contributes to left ventricular (LV) geometry, 60 outpatients with untreated, mild to moderate essential hypertension and 45 normotensives were studied. Based on echocardiographic LV mass index and relative wall thickness, four patterns of LV geometry, i.e., normal left ventricle, concentric remodeling, eccentric hypertrophy and concentric hypertrophy, were identified. Plasma volume and blood volume were measured by the 1311 labeled human serum albumin technique. LV end-diastolic volume was greater in patients with eccentric hypertrophy than in the groups of patients with normal left ventricles, concentric remodeling, or concentric hypertrophy or in normotensive subjects. No differences were found in systolic function among the five groups. Both plasma volume and blood volume were decreased in the concentric remodeling group as compared with the other four groups. However, there were no differences in plasma volume or blood volume among the normal left ventricle, eccentric hypertrophy and concentric hypertrophy groups. These data indicate that a small LV chamber in cases of "concentric remodeling" may be related to decreased plasma and blood volumes, but an enlarged LV chamber in cases of "eccentric hypertrophy" is not likely to be related to either plasma or blood volume levels in mild to moderate untreated essential hypertension.