Sauer William H, Lowery Christopher M, Bargas Royce L, Schuller Joseph L, Stees Christoper S, Aleong Ryan G, Varosy Paul D
University of Colorado, Aurora, Colorado 80045, USA.
Pacing Clin Electrophysiol. 2011 Feb;34(2):186-92. doi: 10.1111/j.1540-8159.2010.02917.x. Epub 2010 Oct 7.
Implantable cardioverter-defibrillators (ICDs) can provide life-saving therapies for ventricular arrhythmias. Arrhythmia induction and defibrillation threshold testing is often performed at implantation and postoperatively during long-term follow-up to ensure proper device function.
We sought to evaluate the prevalence and predictors of occult device malfunction at follow-up defibrillation testing in asymptomatic individuals. A cohort of 853 patients underwent 1,578 defibrillation tests during the 13-year study period. Defibrillation efficacy was evaluated primarily by the two-shock (2S) method, with an adequate safety margin ≥ 10 joules (J) less than the maximum energy delivered by the ICD.
A total of 38 testing failures requiring intervention were discovered during testing (2.4% of all tests). There were 11 ICD system failures resulting in failure to defibrillate, six with underdetection of ventricular fibrillation, and 21 clinically significant increases in defibrillation threshold. There was a higher incidence of failure in older ICD systems (1996-2002) compared to newer ICD systems (2003-2009), reaching statistical significance (3.6% vs 1.0%; P < 0.01). There were 178 subjects (20.8%) with a >20-J safety margin on previous testing, detected R waves >7.0 mV, and all system components implanted after 2003 at the time of testing who did not have any testing failures (0% vs 5.6%; P < 0.01).
Postoperative defibrillation testing identifies a small number of ICD malfunctions in asymptomatic individuals. ICD testing failure is seen more frequently in older systems and in those with borderline results from prior interrogation or testing. These findings suggest that serial postoperative defibrillation testing is not indicated in asymptomatic patients without suspicion for specific problems.
植入式心脏复律除颤器（ICD）可为室性心律失常提供挽救生命的治疗。心律失常诱发和除颤阈值测试通常在植入时及术后长期随访期间进行，以确保设备功能正常。
我们试图评估无症状个体在随访除颤测试中隐匿性设备故障的发生率及预测因素。在13年的研究期间，一组853例患者接受了1578次除颤测试。除颤效果主要通过双次电击（2S）方法评估，安全裕度充足定义为比ICD输送的最大能量少≥10焦耳（J）。
测试期间共发现38次需要干预的测试失败情况（占所有测试的2.4%）。有11次ICD系统故障导致无法除颤，6次对室颤检测不足，21次除颤阈值出现具有临床意义的升高。与新型ICD系统（2003 - 2009年）相比，旧型ICD系统（1996 - 2002年）的失败发生率更高，差异具有统计学意义（3.6%对1.0%；P < 0.01）。在之前测试中安全裕度>20 J、检测到的R波>7.0 mV且测试时所有系统组件均于2003年后植入的178名受试者中，未出现任何测试失败情况（0%对5.6%；P < 0.01）。
术后除颤测试可识别无症状个体中少数ICD故障。ICD测试失败在旧系统以及之前问询或测试结果临界的个体中更常见。这些发现表明，对于没有特定问题疑虑的无症状患者，不建议进行系列术后除颤测试。
