单双相电震除颤对心肌损伤的研究

A Study on Myocardial Injury from Defibrillation of Monophasic and Biphasic Shocks

对 30只太湖猪进行单双相电震心脏除颤 ,采用病理检查、心电图记录以及除颤前后肌酸磷酸酶及其同工酶 ( CPK和 CPK- MB)测定来评价心肌损伤。肉眼观察和显微镜检查发现 ,单双相电震都有心内膜水肿、心肌出血、局部心肌断裂及退行性病变等病理变化。但双相电震效果明显好于单相电震 ,单相电震的 4只猪 (除颤 9～ 1 2次 ,能量 2 0～ 5 0 J)心肌变软 ,切开后可见凝血 ,心内膜附有血栓 ,体外除颤时有 5只猪 (除颤 5次 ,能量 360 J)局部心肌断裂 ;而双相电震的体内和体外各有一只发生心肌退行性病变。心电图记录到单相电震 4只猪发生 ST段压低或 ST段抬高和 2只房室阻滞 ;双相电震时 ,心电图发生的变化分别为 2只 ST段压低和 1只房室阻滞。而 CPK和 CPK- MB检测数值相差较大 ,未作具体评价。本实验提示 :双相电震引起的心肌损伤好于单相电震 ;损伤可能由热和电等因素造成 ;除颤总能量相仿 ,用高能量少次数的除颤方法比低能量多次数对心肌的损伤要大 ;损伤部位可以愈合。

During the defibrillation of monophasic and biphasic in 30 pigs, three methods for the evaluation of myocardial injury were used: pathological examination, defibrillation electrocardiogram recording, and creatine phosphokinase (CPK) and CPK-MB detection before and after defibrillation. Through visual observation and microscope examination, monophasic and biphasic shocks may cause endocardial edema, thrombosis, localized fragmentation of myocardium and retrograde changes. But the result in biphasic shock was better than monophasic's. Soft myocar-dium and endocardium with thrombi was detected in 4 pigs (9～12 shocks ,20～50J). Fragmentation of myocardium was observed in the surface of 5 pigs' defibrillation (5 shocks, 360J). In the biphasic and monophasic defibrillation, retrograde changes were detected in 2 pigs. ST-T segment changed in electrocardiogram in 4 pigs and blockade appeared between ventricle and auricle in 2 pigs after monophasic shock. In biphasic shock, 2 pigs and 1 pig obtained respectively. Because CPK and CPK-MB varied in large range, the dates were not evaluated. This results suggest that the biphasic shock cause lower myocardial injury than monophasic shockdo, with heat and electricity as possible causative factors.When the total energy is same, the defibrillation with high energy and little times can cause bigger myocardial injury than the defibrillation with low energy and more times; the injury may be healed.