门冬氨酸钾镁对肥厚心肌室性心律失常的抑制作用

目的:观察口服门冬氨酸钾镁对肥厚心肌室性心律失常的影响并探讨门冬氨酸钾镁抗心律失常的作用机制。方法:将家兔随机分为假手术组、心肌肥厚组和门冬氨酸钾镁组。假手术组开腹但不行腹主动脉缩窄术,心肌肥厚组和门冬氨酸钾镁组采用腹主动脉缩窄术制备家兔心肌肥厚模型,喂养8周,制备兔左心室楔形心肌块,利用浮置玻璃微电极法同步记录楔形心肌块跨壁心电图和内、外膜心肌细胞跨膜动作电位,观察各组QT间期和内、外膜心肌细胞跨膜动作电位以及跨室壁复极离散度(TDR),程序电刺激诱发室性心律失常,记录早期后除极(EAD)和尖端扭转型室性心动过速(TDP)的诱发率。结果:门冬氨酸钾镁组和心肌肥厚组QT间期和内、外膜心肌细胞跨膜动作电位复极90%时程(APD90)和TDR较假手术组明显延长(均P<0.01)。门冬氨酸钾镁组与心肌肥厚组相比以上各项指标均明显缩短(均P<0.05)。假手术组、心肌肥厚组和门冬氨酸钾镁组EAD的发生率分别为0、100%和50%,TDP的发生率分别为0、40%和10%。心肌肥厚组与假手术组相比差异有统计学意义(P<0.01),门冬氨酸钾镁组与心肌肥厚组相比EAD和TDP的发生率明显降低(P<0.01)。结论:肥厚心肌TDR增大,心律失常的发生率显著升高。门冬氨酸钾镁降低TDR,可明显降低EAD和TDP的发生率。

Inhibitive effects of sparagin on ventricular arrhythmias in hypertrophic rabbits heart

Objective:To observe the effects of sparagin on ventricular arrhythmias in rabbits with hypertrophic myocardium and study the antiarrhythmias mechanism of sparagin.Method:All rabbits were randomly divided into sham-operation(SHAM), cardiac hypertrophy(CH) and sparagin group. In CH and sparagin group, abdominal aorta was partially constricted to make hypertrophic heart of rabbit model, and in SHAM group, the abdominal aorta was only exposed without constrition. All rabbits were fed for eight weeks. By using arterially perfused rabbit ventricular wedge preparations. The transmural ECG, QT interval and transmembrane action potentials (TAP) from epicardium and endocardium were simultaneously recorded. The transmural repolarization dispersion(TDR)and the induced incidence of EAD and TDP were observed.Result:The APD90 and QT interval were significantly prolonged and the TDR was increased in CH group. The APD90,QT interval and the TDR were significantly decreaced in sparagin group compared with those in CH group. Ventricular arrhythmias in cardiac hypertrophy were significantly suppressed by potassium magnesium aspartate.Conclusion:TDR and the incidence of arrhythmias were increased in hypertrophy heart. sparagin diminished TDR and the incidence of EAD and TDP.