由心电图静音60Hz心内泄漏电流引起的心血管崩. 对电气安全的影响
C D Swerdlow1, W H Olson, M E O'Connor
1Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA. swerdlow@ucla.edu
Circulation
|May 20, 1999
概括
目前对心内泄漏电流 (50微A) 的安全标准可能无法保护患者,因为在较低水平时可能会发生心室性心力衰竭等有害影响. 根据连续捕获值提出了20微A的修订标准.
科学领域:
- 生物医学工程 生物医学工程
- 心脏病学 心脏病学
- 医疗器械安全 医疗器械安全
背景情况:
- 对于60Hz内心泄漏电流的确定的安全标准是在单故障条件下为50微A.
- 该标准旨在防止患者因交流电 (AC) 引起的不适.
- 人类的最低不安全的AC水平仍未确定.
研究的目的:
- 在接受植入式心脏转换器-除器测试的患者中确定60Hz交流电 (AC) 的最低不安全水平.
- 评估心内AC对心脏功能和患者安全的影响.
主要方法:
- 研究了40名接受植入式心脏转换器-除器测试的患者.
- 可编程的60Hz交流电被应用在5秒间隔,增加强度.
- 测试了两种当前路径:双极和单极,并监测反应,直到达到心室动 (VF) 或1mA.
主要成果:
- 间歇性心室捕获发生在20微A,连续捕获在32微A,和VF在49微A.
- 连续捕获导致心血管崩 (潜在腹腔动脉短心) 没有心电图刺激的证据.
- 在22%的双极AC患者和12%的单极AC患者中,连续捕获值为≤50微A.
结论:
- 心内泄漏电流在低于VF值的水平上可能导致心血管崩.
- 沉默的AC刺激可能表现为低血压室内心动力减速.
- 目前50微A的安全标准可能不足;根据连续捕获值,建议修订≤20微A的标准.
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