Plasma volume in chronic arterial hypertension.

The plasma volume (PV) was determined in 109 patients with chronic arterial hypertension (AH) by 131I-labeled serumalbumin, expressing the results in ml/cm body height. An attempt was made to establish a statistical correlation between PV and diastolic pressure (DP). In essential AH three types of PV were found: normal, hypovolemic and hypervolemic; in hypertensive patients with stenosis of the renal aorta and in those with pheochromocytoma PV was slightly diminished; in hyperaldosteronism it was increased. In AH due to renal parenchymatous lesions the mean PV values were normal, a positive correlation being found between PV and DP (r + 0.929 and p = 0.05) in contrast to the other types of AH, where r was non significant or negative (stenosis of the renal artery, pheochromocytoma, malignant AH).