EFFECT OF ENALAPRIL MALEATE ON CEREBRAL BLOOD-FLOW IN PATIENTS WITH CHRONIC HEART-FAILURE

The effect of enalapril on cerebral blood flow (CBF) was studied in 11 patients with chronic heart failure (NYHA II pr III, dilated cardiomy opathy in 6 and old myocardial infarction in 5). CBF was evaluated by analyzing the Patlak-Plot curve obtained from radionuclide angiography with technetium-99m hexamethylpropylene amine oxime (Tc-99m-HM-PAO). Cardiac index (CI) and stroke volume (SV) were simultaneously measured by impedance cardiography. These measurements were performed before a nd at four weeks after daily administration of 5 mg enalapril. The str oke volume, cardiac index, and heart rate were not significantly chang ed after four weeks of enalapril administration. However, CBF was incr eased by 6.5% from 36.72 +/-4.66 to 39.13 +/-5.65 mL/100g/min (P<0.05) . These results suggest that enalapril increased cerebral blood flow, which was not related to increased cardiac output in congestive heart failure. Patlak-Plot analysis of radionuclide angiography using Tc-99m -HM-PAO may be available for quantitative assessment of brain perfusio n.