Effect of angiotensin converting enzyme inhibition on the Doppler waveformin dogs with renal artery stenosis

Our objective was to investigate whether the angiotensin converting enzyme inhibitor enalaprilat improves detection of hemodynamically significant ren al artery stenoses in dogs. Renal artery stenoses of 50 to 99% were surgica lly created unilaterally in five dogs. Doppler ultrasonographic evaluation was performed at baseline (no stenosis), after creation of the stenosis, an d after the administration of enalaprilat. The resistive index increased in the nonstenotic kidney (P < 0.01) but not in the stenotic kidney after adm inistration of enalaprilat. The difference in resistive indices between non stenotic and stenotic kidneys increased significantly (P < 0.05) after admi nistration of enalaprilat. Measurement of the resistive index after adminis tration of an angiotensin converting enzyme inhibitor in humans may improve the performance of Doppler ultrasonography in detecting hemodynamically si gnificant renal artery stenoses.