Kirilmaz Ata, Dokumaci Barbaros, Uzun Mehmet, Kilicaslan Fethi, Dinckal M Hakan, Yucel Ozcan, Karaca Mustafa
Cardiology Department, Gülhane Military Medical School, Istanbul, Turkey.
Pacing Clin Electrophysiol. 2005 Jun;28(6):498-505. doi: 10.1111/j.1540-8159.2005.50008.x.
This study was designed to test defibrillation threshold (DFT) with the least number of fibrillation inductions using upper limit of vulnerability (ULV) and to describe the most practical set of ICD during DFT following implantation.
Although the correlation between ULV and DFT has been well described, there has been no uniform DFT testing protocol taking the advantage of ULV after defibrillator (ICD) implantation.
A total of 26 patients undergoing a new ICD implantation had a DFT induced with scanned T wave shock. The hypothesis that ventricular fibrillation (VF) could be defibrillated with 5 J higher than the highest T wave shock needed to induce VF or with 10 J if the T wave shock needed to induce VF was less than 5 J, was tested and 20 patients fulfilled these criteria. The methodology is improved by detecting peak T wave with 12-lead ECG, applying biphasic T wave shock and scanning the T wave shock in a wider window.
Five patients in the first group (n = 15) and one patient in the second group (n = 11) did not fulfill the above hypothesis. The common features of six patients who did not fulfill the hypothesis were that T wave shock needed to induce VF was either under 5 J (5 patients) or high (1 patient).
This study revealed the importance of methodology in studies regarding ULV and DFT. Following ICD implantation, we propose the first biphasic T wave detected by 12-lead ECG and rescue shock set at 10 and 15 J, respectively. If any of the scanned T wave (40 ms before and 40 ms after the peak T wave with decrements and increments of 20 ms) shocks could not induce VF, then the T wave and the first rescue shock should be set at 5 and 10 J, respectively. If the induction of VF has been unsuccessful with T wave shock at 5 J, then a safe defibrillation with 10 J should be expected in majority.
本研究旨在使用易损性上限（ULV）以最少的室颤诱发次数来测试除颤阈值（DFT），并描述植入后DFT期间最实用的植入式心律转复除颤器（ICD）设置。
尽管ULV与DFT之间的相关性已有详尽描述，但在植入除颤器（ICD）后，尚未有利用ULV的统一DFT测试方案。
共有26例接受新ICD植入的患者通过扫描T波电击诱发DFT。对室颤（VF）能否用比诱发VF所需的最高T波电击高5 J的能量除颤，或者若诱发VF所需的T波电击小于5 J则用10 J能量除颤这一假设进行了测试，20例患者符合这些标准。通过12导联心电图检测T波峰值、应用双相T波电击并在更宽窗口内扫描T波电击来改进方法。
第一组（n = 15）中的5例患者和第二组（n = 11）中的1例患者未符合上述假设。6例未符合假设的患者的共同特征是诱发VF所需的T波电击要么低于5 J（5例患者）要么很高（1例患者）。
本研究揭示了方法学在关于ULV和DFT的研究中的重要性。ICD植入后，我们建议通过12导联心电图检测到的首个双相T波，以及分别设置为10 J和15 J的抢救电击。如果任何扫描的T波（在T波峰值前40 ms和后40 ms，以20 ms的递减和递增）电击不能诱发VF，那么T波和首个抢救电击应分别设置为5 J和10 J。如果用5 J的T波电击未能成功诱发VF，那么多数情况下预计用10 J可安全除颤。
