Leitch J W, Yee R
Newcastle University, New South Wales, Australia.
J Am Coll Cardiol. 1993 Jun;21(7):1632-7. doi: 10.1016/0735-1097(93)90379-f.
The objective of this study was to identify predictors of defibrillation threshold in patients undergoing epicardial defibrillator implantation.
Factors that predict epicardial defibrillation efficacy are poorly defined.
The data from 375 consecutive adult patients were reviewed. After exclusion of 137 patients in whom defibrillation threshold was not obtained, 238 patients (32 women and 206 men) with a mean age of 58.9 +/- 13.3 years formed the study group. Coronary heart disease was present in 175 patients and the mean left ventricular ejection fraction was 35.8 +/- 15.4%. At device implantation, three epicardial patch sizes were available and shocks could be delivered over one current pathway (two patches) or over two current pathways (three patches with simultaneous or sequential shocks). Defibrillation threshold was defined as the lowest programmed energy that successfully defibrillated the heart, provided there had been an unsuccessful shock at a lower energy level or successful defibrillation at < or = 5 J.
The mean defibrillation threshold was 8.6 +/- 5.3 J. With univariate analysis, female gender, sequential shocks with three patches, higher left ventricular ejection fraction and lower New York Heart Association functional class predicted a lower defibrillation threshold. In the multivariate analysis, female gender (coefficient -3.9; 95% confidence interval [CI] -1.9 to -5.0 J), ejection fraction (coefficient -0.6; CI -0.1 to -1.0 J/decile) and sequential shocks (coefficient -2.5; CI -1.0 to -4.0 J) were independently associated with a lower defibrillation threshold. Total epicardial patch conductive surface area normalized to body surface area reached borderline significance (coefficient 0.004; CI 0 to 0.01; p = 0.10). Antiarrhythmic drug use, including amiodarone, did not predict defibrillation threshold.
Female gender, high left ventricular ejection fraction and the use of sequential pulse shocks were important determinants of improved defibrillation efficacy.
本研究的目的是确定接受心外膜除颤器植入患者的除颤阈值预测因素。
预测心外膜除颤效果的因素尚不明确。
回顾了375例连续成年患者的数据。排除137例未获得除颤阈值的患者后，238例患者（32例女性和206例男性）组成研究组，平均年龄58.9±13.3岁。175例患者患有冠心病，平均左心室射血分数为35.8±15.4%。在植入装置时，有三种心外膜贴片尺寸可供选择，电击可通过一条电流路径（两片贴片）或两条电流路径（三片贴片，同时或顺序电击）进行。除颤阈值定义为成功使心脏除颤的最低程控能量，前提是在较低能量水平时有一次不成功的电击或在≤5J时成功除颤。
平均除颤阈值为8.6±5.3J。单因素分析显示，女性、三片贴片顺序电击、较高的左心室射血分数和较低的纽约心脏协会功能分级预测较低的除颤阈值。多因素分析显示，女性（系数-3.9；95%置信区间[CI]-1.9至-5.0J）、射血分数（系数-0.6；CI-0.1至-1.0J/十分位数）和顺序电击（系数-2.5；CI-1.0至-4.0J）与较低的除颤阈值独立相关。归一化至体表面积的心外膜贴片总导电表面积达到临界显著性（系数0.004；CI0至0.01；p=0.10）。使用抗心律失常药物，包括胺碘酮，不能预测除颤阈值。
女性、高左心室射血分数和顺序脉冲电击的使用是改善除颤效果的重要决定因素。
