technetium-tc-99m-exametazime and Heart-Failure

The effect of enalapril on cerebral blood flow (CBF) was studied in 11 patients with chronic heart failure (NYHA II or III, dilated cardiomyopathy 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 (99mTC-HM-PAO). Cardiac index (CI) and stroke volume (SV) were simultaneously measured by impedance cardiography. These measurements were performed before and at four weeks after daily administration of 5 mg enalapril. The stroke volume, cardiac index, and heart rate were not significantly changed after four weeks of enalapril administration. However, CBF was increased 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 99mTC-HM-PAO may be available for quantitative assessment of brain perfusion.

Topics: Aged; Angiotensin-Converting Enzyme Inhibitors; Blood Flow Velocity; Cardiac Output; Cardiomyopathy, Dilated; Cerebrovascular Circulation; Chronic Disease; Enalapril; Female; Heart Failure; Heart Rate; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Angiography; Stroke Volume; Technetium Tc 99m Exametazime