Study of DFT energy during ICD implant

在植入式心律转复除颤器（ICD）植入过程中，有必要测量除颤阈值（DFT）。测定DFT需要反复诱导心室颤动和使用高能量电击去颤。这些可能导致脑缺血和心肌损伤。近年来的研究表明，动物模型的脆弱性上限（ULV）与DFT密切相关。我们研究了人类是否存在ULV，以及ULV是否可以准确预测ICD植入期间的DFT。我们对危及生命的室性心律失常进行了ICD植入。在植入过程中，通过延迟四集上下算法确定与50%达到ULV概率（ULV50）和50%达到DFT概率（DFT50）相关的冲击强度。每种情况下都存在ULV。ULV50为3.8 <正负> 2.0J， DFT50为6.5 <正负> 4.9J。ULV50与DFT50的相关性有统计学意义（r=0.99， P<0.0001, DFT50=-2.97*2.45ULV50）结论：测量UVL可作为ICD植入过程中测量DFT的替代方法，并可显著减少测量次数。测定DFT所需的VF感应和冲击。因此，我们正在考虑利用多通道映射装置分析除颤的机理。

It is necessary to measure defibrillation threshold (DFT) during implantation of the implantable cardioverter defibrillator (ICD). Determination of DFT requires repeated induction of ventricular fibrillation and defibrillation attempts using high-enrergy shocks. These may lead to cerebral ischemia and myocardial damage. In recent studies, uppper limit of vulnerability (ULV) has been shown to closely correlate with DFT in aminal models.We examined whether ULV is present in human and whether ULV can be used to accurately predict DFT during implantation of ICD.We underwent the ICD implantation for life-threatening ventricular arrhythmia. During the implantation, the shock strength associated with a 50% probabirity of reaching ULV (ULV50) and a 50% probabirity of reaching DFT (DFT50) were determined by the delayd four-episode up down algorithm.ULV existed in each cases. ULV50 was 3.8 <plus-minus> 2.0J and DFT50 was 6.5 <plus-minus> 4.9J.The correlation between ULV50 and DFT50 is signific(r=0.99, P<0.0001, DFT50=-2.97*2.45ULV50)Conclution : Measurement of UVL can be used as a substitutes for measurement of DFT during implantation of ICD,and significantly reduce the number of. VF induction and shock required to determinarion of DFT.Therefore, we are thinking to analyze the mechanism of defibrillation using multi-channel mapping device.