Abnormal captopril renogram in a patient without renovascular hypertension

Captopril renal scintigraphy is a well-known noninvasive tool in the diagnosis of renovascular hypertension. The authors present a case of a patient with malignant hypertension whose captopril renal scintigraphy suggested bilateral and equal renovascular hypertension. His renal angiogram, however, demonstrated no renal artery stenosis or abdominal aortic atherosclerotic disease. False-positive captopril renal scintigraphy has been reported but can usually be attributed to the patient's hypotensive episode after captopril administration, volume or salt depletion, or chronic glomerulonephropathy. This patient demonstrated mild blood pressure changes after captopril administration and was not volume or salt depleted. His creatinine was 1.6 mg/dl on admission but demonstrated appropriate renal function on subsequent noncaptopril renal scintigraphy.