Increased sympathetic nerve activity in renovascular hypertension

Background-increased sympathetic nerve activity may contribute to the progr ession of renovascular hypertension. Because previous results have been inc onclusive, we investigated whether renovascular hypertensives show increase d total and regional sympathetic nerve activity. Methods and Results-Sixty-five patients underwent renal angiography and mea surements of plasma renin activity and angiotensin II in conjunction with e stimation of sympathetic nerve activity by means of radiotracer dilution an d intraneural recordings of muscle sympathetic nerve activity (MSNA), Age-m atched healthy subjects (n=15) were examined for comparison. Total body nor epinephrine (NE) spillover, an index of overall sympathetic nerve activity, was increased by 100% and MSNA by 60% in the hypertensive patients compare d with healthy subjects (P<0.01 for both). A subgroup of 24 patients with w ell-defined renovascular hypertension (cured or improved hypertension after renal angioplasty) showed similar increases in total body NE spillover com pared with the group at large. Patients with arterial plasma renin activity and angiotensin II levels above median had higher values for total body NE spillover than patients below median (P<0.01). Conclusions-This study unequivocally demonstrates elevated sympathetic nerv e activity in patients with renovascular hypertension. The adrenergic overa ctivity may contribute to the blood pressure elevation and perhaps also to the high cardiovascular mortality in renovascular hypertension.