Left ventricular function and the distribution of pulmonary and total blood volume in hypertensive and normotensive man.

Using radionuclide methods the relationship between total and central blood volume and left ventricular function was studied in 12 patients with untreated essential hypertension and contrasted with the findings in eight normotensive subjects. The principal findings were of an increased stroke volume and end-diastolic volume with an increase in the ratio of pulmonary to total blood volume in the hypertensive patients. Left ventricular ejection fraction was similar in both groups but end-systolic volume was increased presumably in response to the increased afterload of the ventricle. The increased pulmonary blood volume may be secondary to altered left ventricular mechanics and not a primary determinant of cardiac function.