[Effects of tetraethylammonium chloride and verapamil on the effective refractory period of ischemic myocardium in rabbits].

The effects of potassium ion channel blocker TEA and calcium ion channel blocker verapamil on effective refractory period (ERP) of ischemic ventricular muscle were studied in rabbits. The results showed that ERP of the ventricular muscle in central ischemic zone (CIZ) and border ischemic zone (BIZ) were shortened, respectively, at 10 min and 30 min after coronary occlusion (P < 0.01). The changes of ERP in TEA-treated and verapamil-treated rabbits after coronary occlusion were found to be significantly less than those in untreated rabbits. The results suggest that TEA and verapamil alleviated the degree of ERP shortening after coronary occlusion and may exhibit protective effects on the ischemic myocardium.