Jones D L, Sohla A, Klein G J
Pacing Clin Electrophysiol. 1986 May;9(3):322-31. doi: 10.1111/j.1540-8159.1986.tb04487.x.
The influence of myocardial ischemia on defibrillation success was studied using two different lead orientations in halothane-anesthetized pigs. Ischemia was induced by ligating the left anterior descending artery in its distal third. Controls had loosely tied ligatures placed around the artery at the same site. Ventricular fibrillation was induced by electrical stimulation 30 minutes after coronary artery ligation. Defibrillation used a single truncated pulse of approximately 6 ms duration passed to either: a transvenous electrode catheter (Medtronic, 6880) with the cathode in the apex of the right ventricle and the anode in the superior vena cava-atrial junction region, or the cathode in the apex of the right ventricle and a mesh plaque on the epicardium of the basal lateral left ventricle as anode. Ten seconds after the onset of ventricular fibrillation, defibrillation was attempted with increasing incremental energies until defibrillation was achieved. Fibrillation episodes were repeated at 15-minute intervals until the minimum first shock was successful in defibrillating the animal (i.e., defibrillation threshold). The number of animals successfully defibrillated with a minimum energy above or below 30 J was not different between normal and ischemic animals for either electrode configuration (i.e., 3 out of 20 vs 1 out of 13 for the catheter and 5 out of 6 vs 6 out of 7 for the epicardial plaque, respectively). Also, the cumulative percent success as a function of defibrillation energy was similar in both the normal and ischemic groups. There was a significant reduction in the minimum energy necessary for defibrillation when passing current between the right ventricular apex and the left ventricular epicardial plaque. The present results indicate that, despite differences in lead orientations, acute ischemia in the anesthetized pig does not appear to influence defibrillation success.
在氟烷麻醉的猪中，使用两种不同的导联方向研究心肌缺血对除颤成功率的影响。通过结扎左前降支动脉的远端三分之一诱导缺血。对照组在同一部位对动脉进行松扎。冠状动脉结扎30分钟后，通过电刺激诱发心室颤动。除颤采用单个持续时间约6毫秒的截断脉冲，该脉冲施加于以下两种情况之一：一种是经静脉电极导管（美敦力公司，6880型），其阴极位于右心室心尖，阳极位于上腔静脉与心房交界处；另一种是阴极位于右心室心尖，阳极是左心室基底外侧心外膜上的网状板。心室颤动发作10秒后，以递增的能量尝试除颤，直至成功除颤。以15分钟的间隔重复颤动发作，直到最小的首次电击成功使动物除颤（即除颤阈值）。对于两种电极配置，正常动物和缺血动物中以高于或低于30焦耳的最小能量成功除颤的动物数量没有差异（即，导管组中20只中有3只，13只中有1只；心外膜板组中6只中有5只，7只中有6只）。此外，正常组和缺血组中除颤成功率作为除颤能量的函数的累积百分比相似。当电流在右心室心尖和左心室心外膜板之间通过时，除颤所需的最小能量显著降低。目前的结果表明，尽管导联方向不同，但麻醉猪的急性缺血似乎并未影响除颤成功率。
