Dorman B H, Conroy J M, Baker J D, Kratz J M, Leman R B
Department of Anesthesiology, Medical University of South Carolina, Charleston 29425.
South Med J. 1993 May;86(5):533-6. doi: 10.1097/00007611-199305000-00009.
Implantation of automatic internal cardiac defibrillators (AICD) for management of arrhythmias necessitates the induction of ventricular fibrillation (VF) to test the device adequately. The profound hypotension associated with induced arrhythmia and subsequent circulatory arrest may result in cerebral ischemia. To characterize cerebral ischemia, we used a five-lead Lifescan brain activity monitor to examine changes in cerebral activity in 10 patients having AICD placement. The duration of hypotension, as defined by a mean arterial pressure (MAP) < 50 mm Hg, was recorded, and the corresponding changes in brain activity were evaluated during 51 episodes of circulatory arrest. The number of episodes for each patient ranged from 2 to 14. The average duration of hypotension per episode was 26.2 seconds, with a range of 8 to 67 seconds. Brain activity changes characteristic of cerebral ischemia occurred in 46 of the 51 events (90%). Cerebral ischemia did not occur when the duration of hypotension was less than 16 seconds (5 episodes). The duration of cerebral ischemia ranged from 50 to 279 seconds (average 84.9 seconds) and did not correlate with the duration of hypotension or the order of the episodes in the testing sequence. These findings suggest that reevaluation of standard monitoring practice for AICD implantation may be warranted.
植入自动体内心脏除颤器（AICD）以治疗心律失常需要诱发室颤（VF）来充分测试该设备。与诱发心律失常及随后的循环骤停相关的严重低血压可能导致脑缺血。为了描述脑缺血的特征，我们使用五导联生命扫描脑活动监测仪检查了10例植入AICD患者的脑活动变化。记录平均动脉压（MAP）<50 mmHg所定义的低血压持续时间，并在51次循环骤停期间评估相应的脑活动变化。每位患者的发作次数为2至14次。每次发作的平均低血压持续时间为26.2秒，范围为8至67秒。51次事件中有46次（90%）出现了脑缺血特征性的脑活动变化。当低血压持续时间小于16秒时（5次发作）未发生脑缺血。脑缺血持续时间为50至279秒（平均84.9秒），与低血压持续时间或测试序列中发作的顺序无关。这些发现表明可能有必要重新评估AICD植入的标准监测方法。
