[Effects of cibenzoline on myocardial ischemia]

The effect of cibenzoline, an antiarrhythmic drug, on myocardial ischemia was studied in the anesthetized open-chest dog. Ischemia was induced by completely ligating or partially occluding the left anterior descending coronary artery. The levels of ATP and creatine-phosphate decreased, and the ADP and AMP levels increased during ischemia. The level of glycogen was also decreased, and that of lactate was increased by ischemia, resulting in myocardial acidosis. Pretreatment with either 2 mg/kg or 8 mg/kg of cibenzoline prevented the decrease in ATP level and the increase in lactate level. These results suggest that cibenzoline reduces the influence of ischemia on the myocardium.