Normal renin uremic hypertension. Study of cardiac hemodynamics, plasma volume, extracellular fluid volume, and the renin angiotensin system.

Studies were undertaken in 33 uremic patients with or without hypertension, 11 normal subjects, and 15 essential hypertensive patients to assess cardiac hemodynamics, plasma volume, extracellular fluid volume, and peripheral renin levels. Cardiac output and intraarterial blood pressure were measured and peripheral vascular resistance index calculated. These studies suggest that uremic hypertension with normal renin values and hypervolemia is hemodynamically sustained by an increase in peripheral resistance rather than by an increased cardiac output. The renin angiotensin system plays a secondary role as compared to overexpansion in the genesis of hypertension in normoreninemic uremic hypertension.