Hsia H H, Kleiman R B, Flores B T, Marchlinski F E
Clinical Cardiac Electrophysiology Laboratory, Hospital of University of Pennsylvania, Philadelphia.
Pacing Clin Electrophysiol. 1994 Jul;17(7):1222-30. doi: 10.1111/j.1540-8159.1994.tb01489.x.
The defibrillation threshold (DFT) using simultaneous (SIML) versus sequential (SEQ) pathways for shock delivery was compared in 16 patients with an implanted cardioverter defibrillator. All patients had three-lead nonthoracotomy systems (NTL) using a left chest subcutaneous patch, a right ventricular endocardial lead, and a lead in the coronary sinus (n = 5) or superior vena cava (n = 11). The DFT were determined 2-44 days (17 +/- 17 days) after implantation. The DFT was defined as the lowest energy shock that resulted in successful defibrillation. The first pathway tested was SIML in 12 and SEQ in 4 patients with output beginning at or above the intraoperative DFT, routinely 18 J. The second pathway was tested beginning 2-4 J above the DFT of the first tested pathway. All shocks were delivered in 2-4 J decrement or increment steps. The SEQ pathway shocks resulted in a significantly lower DFT than SIML pathway shocks (14 +/- 6 vs 18 +/- 6 J; P < 0.01). There was no difference in the time delay after ventricular fibrillation initiation before shock delivery for the successful defibrillation between SIML versus SEQ pathways (7 +/- 2 secs for both pathways). In 7 of 16 patients, defibrillation using SEQ pathway resulted in a > 5 J lowering of DFT, while only one patient had > 5 J lowering of DFT using SIML shocks (P < 0.05). These results have important implications for selecting the optimal pathway for implantable cardioverter defibrillator therapy with a multilead NTL system.
在16例植入式心脏复律除颤器患者中，比较了采用同步（SIML）与顺序（SEQ）电击传导通路时的除颤阈值（DFT）。所有患者均使用三导联非开胸系统（NTL），该系统采用左胸皮下贴片、右心室心内膜导联以及位于冠状窦（n = 5）或上腔静脉（n = 11）的导联。在植入后2 - 44天（17±17天）测定DFT。DFT定义为能成功除颤的最低能量电击。首先对12例患者测试的通路为SIML，4例患者测试的通路为SEQ，输出能量从术中DFT或高于术中DFT开始，通常为18 J。第二条通路从比第一条测试通路的DFT高2 - 4 J开始测试。所有电击均以2 - 4 J的递减或递增步长进行。SEQ通路电击导致的DFT显著低于SIML通路电击（14±6 J对18±6 J；P < 0.01）。在SIML与SEQ通路成功除颤时，心室颤动起始至电击发放的时间延迟无差异（两条通路均为7±2秒）。在16例患者中的7例，使用SEQ通路除颤使DFT降低> 5 J，而使用SIML电击仅有1例患者的DFT降低> 5 J（P < 0.05）。这些结果对于选择多导联NTL系统植入式心脏复律除颤器治疗的最佳通路具有重要意义。
