卡维地洛对阿霉素心肌病兔心脏结构及电稳定性的影响

Effect of carvedilol on cardiac structure and electrical stability in rabbit with adriamycin cardiomyopathy

目的探讨卡维地洛对阿霉素心肌病兔心脏结构及电稳定性的影响。方法 40只日本长耳白兔随机分为空白对照组、空白模型组、倍他乐克组和卡维地洛组,每组10只。采用耳缘静脉注射阿霉素(1mg/kg,每周2次,共16次)建立阿霉素心肌病模型。3周后倍他乐克组和卡维地洛组分别给予倍他乐克(5 mg.kg-1.d-1)和卡维地洛(5 mg.kg-1.d-1)灌胃,空白对照组和空白模型组每日以等容量生理盐水灌胃,给药2个月后制备兔左室楔形心肌块的灌注模型,同步记录心内、外膜动作电位及跨室壁心电图、跨室壁离散度(TDR),并记录快频率程序刺激下触发活动和室性心律失常的发生率。结果空白对照组、空白模型组、倍他乐克组和卡维地洛组触发活动发生率分别为0/10、10/10、9/10和4/10,室性心律失常发生率分别为0/10、9/10、7/10和2/10。与空白对照组比较,阿霉素组触发活动和室性心律失常的发生率明显增加;与空白模型组比较,倍他乐克组无显著性差异,而卡维地洛组触发活动和室性心律失常的发生率明显降低(P均<0.05)。结论卡维地洛能改善阿霉素心肌病引起的心脏结构改变,并有效抑制室性心律失常的诱发。

Objective To investigate the effects of carvedilol on cardiac structure and electrical stability in rabbits with adriamycin cardiomyopathy. Methods Forty Japanese white rabbits were randomly divided into four groups （ n = 10 each） ： the control group, the adriamycin group, the metoprolol group and the carvedilol group. Rabbits in the adriamycin group, the metoprolol group and the carvedilol group were intravenously injected at auri-edge with adriamycin hydrochloride （ 1 mg/kg） twice a week for 8 weeks, the control group was injected with equal saline at the same timepoint. Thereafter, rabbits in the metoprolol group and the carvedilol group were intragastrically administrered with metoprolol and carvedilol （ 5 mg· kg^-1·d^-1 ） respectively, and those in the control group and the adriamycin group were intragastrically administr- ered with equal volume of saline. Two months later, wedge preparations from the rabbit heart were perfused with Tyrode＇s solution, transmural electrocardiogram, QT interval, transmural repolarization dispersion（TDR） and the incidences of triggered activity（TA） and ventricular arrhythmias （VA） were recorded. Results TA and VA were not induced in the control group. The incidence of TA and VA oc- curred in 10/10 and 9/10 rabbits in adriamycin group, in 9/10 and 7/10 rabbits in the metoprolol group, and in 4/ 10 and 2/10 rabbits in the carvedilol group respectively. The incidences of TA and VA in the adriamycin group were significant higher than those in the control group.However, the two incidences were significantly lower in the carvedilol group when compared with those in the adriamycin group. Conclusions Carvedilol can improve abnormal cardiac structure and inhibit VA in rabbit with adriamycin cardio- myopathy.