Effect of beta-blockade by metoprolol on global and regional left ventricular myocardial perfusion in coronary heart disease.
Utilizing semiselective 133Xenon injections and gamma camera recording, global and regional left ventricular myocardial perfusion were recorded under the influence of beta-blockade by metoprolol in 9 patients with angiographically proven coronary artery disease. Metoprolol reduced the rate--pressure variable in every patient, the mean reduction amounting to 24% (P less than 0.01). With one exception, the global left ventricular myocardial flow followed the change in the rate-pressure variable. No significant differences were detected in the flow responses of areas distal to only moderate coronary obstructions (less than 75%) and areas distal to significant (less than 75%) obstructions. The same was true when areas of asynergic contractions were compared with areas of normal contractions, or when areas supplied by collaterals were compared with areas devoid of collateral vessels. It is concluded that the reduction in myocardial flow after metoprolol is due to the reduction of the myocardial oxygen consumption, and no redistribution of flow occurs.
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology*; D008875:Middle Aged; D011412:Propanolamines / Q000494:pharmacology*; D011877:Radionuclide Imaging; D014980:Xenon Radioisotopes
D011412:Propanolamines; D014980:Xenon Radioisotopes; D008790:Metoprolol