Reversal of regional myocardial depressant effects of propranolol with nitroglycerin

Abstract Use of propranolol in acute myocardial infarction is limited by its cardiodepressant effects. The effects of nitroglycerin (0.4 mg intravenously) on regional myocardial dysfunction produced by total or partial (50 percent) coronary occlusion and intravenous administration of propranolol (1.0 mg/kg) were evaluated using pairs of ultrasonic crystals implanted subendocardially in the nonischemic and ischemic zones in 14 open chest dogs. During partial coronary occlusion, systolic shortening (%ΔL) in the ischemic zone decreased from 20.9 ± 5.3 to 7.2 ± 6.4 (p