Goldberger J J, Aronson R S
Department of Medicine, Northwestern University Medical School, Chicago, Illinois 60611.
Pacing Clin Electrophysiol. 1992 Feb;15(2):162-70. doi: 10.1111/j.1540-8159.1992.tb03060.x.
Calcium ions appear to play a central role in the development of ventricular arrhythmias associated with digitalis intoxication. Therefore, the effects of the calcium channel antagonist, verapamil, on ouabain-induced ventricular tachycardia were investigated. Ventricular tachycardia (three or more consecutive wide QRS complexes) was induced in guinea pigs by intravenous infusion of ouabain (1 microgram/min) and bursts of rapid ventricular stimulation. Of seven guinea pigs given the infusion of ouabain, all developed ventricular tachycardia at a dose of 82 +/- 17 micrograms/kg (mean +/- SD) and none developed heart block or asystole. Eight guinea pigs were treated with verapamil (2 micrograms/min for 30 minutes) prior to exposure to ouabain. Of those eight animals, only two developed ventricular tachycardia but six developed heart block or asystole at a significantly higher dose of ouabain (154 +/- 47 micrograms/kg). None of three control guinea pigs given an infusion of normal saline for 90 minutes developed ventricular tachycardia. These results show that pretreatment with verapamil inhibits ouabain-induced ventricular tachycardia in guinea pigs. Combined treatment with verapamil and ouabain is associated with a high incidence of heart block and asystole, which may limit the usefulness of verapamil.
钙离子似乎在与洋地黄中毒相关的室性心律失常的发生中起核心作用。因此，研究了钙通道拮抗剂维拉帕米对哇巴因诱导的室性心动过速的影响。通过静脉输注哇巴因（1微克/分钟）和快速心室刺激阵发，在豚鼠中诱发室性心动过速（三个或更多连续的宽QRS波群）。在接受哇巴因输注的七只豚鼠中，所有豚鼠在剂量为82±17微克/千克（平均值±标准差）时均发生室性心动过速，且无一发生心脏传导阻滞或心搏停止。八只豚鼠在接触哇巴因之前接受维拉帕米治疗（2微克/分钟，持续30分钟）。在这八只动物中，只有两只发生室性心动过速，但六只在明显更高剂量的哇巴因（154±47微克/千克）时发生心脏传导阻滞或心搏停止。三只接受90分钟生理盐水输注的对照豚鼠均未发生室性心动过速。这些结果表明，维拉帕米预处理可抑制豚鼠中哇巴因诱导的室性心动过速。维拉帕米和哇巴因联合治疗与心脏传导阻滞和心搏停止的高发生率相关，这可能会限制维拉帕米的实用性。
