动物实验模型中多极导管心室除颤系统电除颤对心脏功能的影响

评价新型的双极和三极导管自动心室除颤系统电除颤对左心室收缩和舒张功能的影响。动物麻醉后,在X光机指导下,分别在10只犬心脏内装置双极导管自动除颤系统（组Ⅰ）;在10只猪心脏内装置三极导管自动除颤系统（组Ⅱ）;并行电除颤试验。使用食管超声心动图在电除颤前后记录二维、M型和多谱勒超声图像。组I动物接受4次电除颤,电量为64J;组Ⅱ接受平均8次电除颤,电量为210J。结果显示：左室收缩面积分数、左室等容舒张时间和二尖瓣血流E波与A波速度比值以及时间-流速积分比值等反映左室舒缩功能的指标在两组动物除颤后均无显著改变。研究表明：两种经静脉导管自动心室除颤系统中反复低能量心内膜电除颤对左室舒缩功能无明显损伤作用;研究结果为经静脉多极导管自动心室除颤系统在临床的应用和电生理研究提供了可靠的实验数据。

Effects of Defibrillation in the Multiple-lead Cardiac Defibrillation Systems on Left Ventricular Function in Animal Model

This study evaluates the immediate effects of the endocardial electrical defibrillation delivered by two transvenous defibrillation systems on left ventricular(LV)function in the animal model.Automatic cardiac defibrillation systems with bipolar leads(group I)and tripolar leads(group II)were placed in the hearts of 10 dogs(group I)and 10 pigs(group II),respectively.Transesophageal echocardiography with two dimensional image,M-mode and pulse Doppler were performed at baseline and after several episodes of defibrillation(DF).Each animal in group1 underwent 4 DF with 64 Joules;the animals in group2 underwent an average of 8 DF with a total of 210 Joules.LV fractional area contraction,isovolumic relaxation time,and both ratios of velocities and time-velocity integrals in transmitral Doppler flow E and A waves exhibited no significant change after the shocks.This study suggests that the repeated low-energy electrical countershocks delivered by two transvenous defibrillation systems do not cause LV global systolic and/or diastolic dysfunction.