ENDOKRINE UND NUKLEARMEDIZINISCHE DIAGNOSTIK DER RENOVASKULAREN HYPERTONIE

To check the reliability of the captopril test and of quantitative radioisotope techniques for the primary diagnosis of renovascular hypertension the data from 41 patients suspected of this disease were retrospectively analysed. In all cases plasma renin activity (PRA) was assayed in peripheral blood and in renal vein blood before and after 25 mg captopril. Double tracer studies with ¹³¹I-hippuran and ^99mTc-DTPA were also performed, as was renal arteriography. The postoperative blood pressure plots of 23 patients with unilateral renal artery stenosis (who had subsequently been operated upon) were included in the evaluation. Renovascular hypertension was diagnosed in 21 patients and essential hypertension in 20. Twelve of the 20 patients with essential hypertension had renal artery stenosis, but this had not produced renovascular hypertension. The diagnostic significance of the tests as markers of renovascular hypertension was as follows: captopril test P < 0.001, glomerular filtration fraction P < 0.02, hippuran clearance P < 0.001. The captopril test and the quantitative radioisotope techniques were in agreement in identifying patients with renal artery stenosis and renovascular hypertension. False-positive results due to methodological shortcomings can be avoided by applying both methods in succession.