Hypotensive response to captopril: A potential pitfall of scintigraphic assessment for renal artery stenosis

A characteristic pattern seen on captopril renography is described that is due to systemic hypotensive response. Most patients with these findings on captopril renography do not receive renal artery angiograms in our clinic b ecause it is usually recognized. However, this pattern has received little attention in the medical literature and may be misinterpreted as being due to physiologically significant renal artery hypertension. Methods: Over the last 3 y, renal artery angiograms were performed on three patients with sy stemic hypotensive response pattern on captopril renography. This allowed a unique opportunity to correlate the results of the captopril renogram with the renal artery angiograms in this patient population, Captopril renograp hy was performed with a glomerular filtration agent, diethylenetriamine pen taacetic acid (DTPA), and a tubular agent, o-iodohipurate (OIH). Results: R enal artery angiograms showed no evidence of renal artery stenosis in three patients with systemic hypotensive response pattern on captopril renograph y, Systemic hypotension on captopril renograms results in preserved uptake of both DTPA and OIH and hyperconcentration in the cortex and collecting sy stem. Conclusion: The systemic hypotensive response pattern seen on captopr il renography is a distinctive pattern that does not represent physiologica lly significant renal artery stenosis.