Lucy S D, Jones D L, Klein G J
Department of Physiology, University of Western Ontario, London, Canada.
Am Heart J. 1994 Feb;127(2):366-76. doi: 10.1016/0002-8703(94)90126-0.
Progressive changes in myopathology after implantation of an automatic defibrillator could compromise device efficacy. The influence of heart failure development on the defibrillation threshold was evaluated by means of a rapid ventricular pacing model of heart failure in dogs. After transvenous pacemaker lead implantation, adult mongrel dogs were randomly assigned to either the control (n = 7) or rapidly paced group (240 beats/min, n = 6). Seventeen days after implantation, triplicate determinations of the defibrillation threshold were made with three epicardial electrodes. The average defibrillation threshold was four times higher in the rapidly paced group, 13.3 +/- 2.0 joules (mean +/- SEM), than in the control group, 3.3 +/- 0.7 joules (p < 0.01), and was significantly correlated with ventricular weight (r = 0.70, p < 0.01). Both defibrillation threshold energy per gram of ventricle and ventricular weight corrected for body weight were significantly higher in rapidly paced dogs compared with control dogs. It was concluded that myocardial hypertrophy and heart failure may profoundly increase defibrillation energy requirements.
植入自动除颤器后心肌病理的进行性变化可能会损害设备的效能。通过犬类心力衰竭的快速心室起搏模型评估心力衰竭发展对除颤阈值的影响。经静脉植入起搏器导线后，成年杂种犬被随机分为对照组（n = 7）或快速起搏组（240次/分钟，n = 6）。植入后17天，使用三个心外膜电极对除颤阈值进行三次重复测定。快速起搏组的平均除颤阈值为13.3±2.0焦耳（平均值±标准误），是对照组3.3±0.7焦耳的四倍（p < 0.01），且与心室重量显著相关（r = 0.70，p < 0.01）。与对照犬相比，快速起搏犬每克心室的除颤阈值能量和校正体重后的心室重量均显著更高。得出的结论是，心肌肥厚和心力衰竭可能会显著增加除颤能量需求。
