Endou K, Yamamoto H, Sato T
Department of Medicine, School of Medicine, Kitasato University, Kanagawa, Japan.
Jpn Heart J. 1987 Sep;28(5):719-35. doi: 10.1536/ihj.28.719.
We studied the effects of Ca channel blockers and 3 antiarrhythmic drugs on the digitalis-induced oscillatory afterpotential (OAP). The OAP was observed in Purkinje fibers stimulated by pulse trains, with cycle lengths ranging from 1,000 to 300 msec. The Ca channel blockers verapamil, diltiazem and nifedipine (2.0 x 10(-6) M) depressed OAP significantly and abolished triggered activity. Verapamil was more effective than diltiazem. However, nicardipine and nitrendipine (2.0 x 10(-6) M) had no depressant effects on OAP or triggered activity. The antiarrhythmic drugs procainamide (1.0 x 10(-4) M), mexiletine (1.0 x 10(-5) M) and propranolol (1.0 x 10(-4) M) depressed both OAP and triggered activity. There were no significant differences in the depressant effects between the Ca2+ antagonists (except for nitrendipine and nicardipine) and the other antiarrhythmic drugs. The OAP coupling interval was prolonged by verapamil, diltiazem, propranolol, procainamide and mexiletine. Although the APD50 was shortened by verapamil, diltiazem and nifedipine, it was prolonged by propranolol. It is concluded that nifedipine, verapamil, diltiazem, procainamide, mexiletine and propranolol may be effective for digitalis-related arrhythmia.
我们研究了钙通道阻滞剂和3种抗心律失常药物对洋地黄诱导的振荡后电位（OAP）的影响。在由周期长度为1000至300毫秒的脉冲串刺激的浦肯野纤维中观察到OAP。钙通道阻滞剂维拉帕米、地尔硫䓬和硝苯地平（2.0×10⁻⁶ M）显著抑制OAP并消除触发活动。维拉帕米比地尔硫䓬更有效。然而，尼卡地平（2.0×10⁻⁶ M）和尼群地平（2.0×10⁻⁶ M）对OAP或触发活动没有抑制作用。抗心律失常药物普鲁卡因胺（1.0×10⁻⁴ M）、美西律（1.0×10⁻⁵ M）和普萘洛尔（1.0×10⁻⁴ M）均抑制OAP和触发活动。钙通道拮抗剂（尼群地平和尼卡地平除外）与其他抗心律失常药物之间的抑制作用无显著差异。维拉帕米、地尔硫䓬、普萘洛尔、普鲁卡因胺和美西律可延长OAP的耦合间期。虽然维拉帕米、地尔硫䓬和硝苯地平缩短了动作电位时程50%（APD50），但普萘洛尔使其延长。结论是硝苯地平、维拉帕米、地尔硫䓬、普鲁卡因胺、美西律和普萘洛尔可能对洋地黄相关心律失常有效。
