Effect of propranolol on regional oxygen balance in the ischemic canine myocardium
Sakata, S.; Toriumi, S.; Takata, K.; Saito, T.; Arase, T.
Masui. Japanese Journal of Anesthesiology 36(1): 39-45
1987
ISSN/ISBN: 0021-4892 PMID: 3560425 Document Number: 292479
Effect of propranolol on regional oxygen balance in the ischemic myocardium, coronary hemodynamics and lactate metabolism were investigated in the buprenorphine-fentanyl-anesthetized dogs. For the evaluation of regional oxygen balance, the oxygen tensions in the subendo- and subepicardium were measured simultaneously with an oxygen electrode. Both the oxygen tensions in the subendo- and subepicardium and lactate extraction ratio in the ischemic area prepared by constriction of the circumflex coronary artery increased significantly with propranolol. These changes were accompanied by reductions in heart rate and cardiac contractility, an elevation of LVEDP and an increase in diastolic/systolic circumflex flow ratio despite no change as a whole. In conclusion the improvement of regional myocardial metabolism in the ischemic area with propranolol is probably due to the decrease in myocardial oxygen consumption which overshadowed the reduction of cardiac contractility and possibly to the blood redistribution to the subendocardium in the affected area.