USE OF A THERMODILUTION RENAL-VEIN CATHETER TO MEASURE RENAL BLOOD-FLOW IN PATIENTS WITH ESSENTIAL-HYPERTENSION

Our objective was to investigate the changes in renal hemodynamics, an d the role of these changes in the pathogenesis of essential hypertens ion. We used a thermodilution renal vein catheter and measured left re nal blood flow in 21 patients with essential hypertension. Arterial pr essure was monitored concurrently. Cardiac output was measured in 11 p atients to calculate total peripheral vascular resistance. Systolic, d iastolic, and mean arterial pressure were 187+/-7 mmHg, 97+/-5 mmHg an d 127+/-5 mmHg, respectively. Left renal blood flow was 8.01+/-0.38 ml /s. Left renal vascular resistance, calculated as mean arterial pressu re divided by left renal blood flow, was 16.4+/-0.8 mmHg ml-(1)s, and was positively correlated with systolic, diastolic and mean arterial p ressures (p<0.05). However, no significant correlation was observed be tween arterial pressure and left renal blood now. Plasma renin activit y in left renal venous blood, measured in 15 patients, was not signifi cantly correlated with renal hemodynamics. Cardiac output and total pe ripheral vascular resistance were 81.4+/-6.0 l/min and 1.68+/-0.18 mmH g ml-(1)s, respectively. Total peripheral vascular resistance was not significantly correlated with either left renal blood flow or renal va scular resistance. The data suggest that a rise in renal vascular resi stance may parallel the rise in blood pressure, but not that of total peripheral vascular resistance.