title: Effect of calcium antagonists on the electrical alternans of the ST segment during acute coronary occlusion in dogs.
abstract: Effects of antagonists on the ST alternans during acute coronary occlusion were examined in dogs. The intravenous administration of verapamil at doses of 0.1 mg/Kg and 0.2 mg/Kg prominently attenuated the degree of alternans. Diltiazem at dose of 0.2 mg/Kg also attenuated the degree of alternans. Dipyridamole at dose of 0.5 mg/Kg did not significantly attenuate the degree of alternans. Verapamil significantly inhibited the ST-segment elevation. After verapamil, ST alternans did not occur even after a longer period of occlusion when changes in QRS complex and the ST-segment elevation were remarkable. It is possible that verapamil inhibits ST alternans by both the protecting effect against ischemic injury and a direct effect on the electrical activity of the myocardial cell membrane.
mesh_terms: D000208:Acute Disease; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors*; D003327:Coronary Disease / Q000503:physiopathology*; D004110:Diltiazem / Q000494:pharmacology; D004176:Dipyridamole / Q000494:pharmacology; D004285:Dogs; D004562:Electrocardiography; D014700:Verapamil / Q000494:pharmacology
chemical_list: D004176:Dipyridamole; D014700:Verapamil; D004110:Diltiazem; D002118:Calcium