Upper limit of vulnerability predicts chronic defibrillation threshold for transvenous implantable defibrillators.
Upper limit of vulnerability predicts chronic defibrillation threshold for transvenous implantable defibrillators.
复制标题
脆弱性上限预测经静脉植入式除颤器的慢性除颤阈值。
DOI：
10.1111/j.1540-8167.1997.tb00786.x
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发表时间：
1997
影响因子：
2.7
通讯作者：
Swerdlow,CD
中科院分区：
文献类型：
--
作者：
Martin,DJ;Chen,PS;Hwang,C;Gang,ES;Mandel,WJ;Peter,CT;Swerdlow,CD
ULV预测慢性DFT。简介：易损性上限（ULV）是指在易损期内施加时不会诱发室颤的电击强度。它与急性除颤阈值（DFT）密切相关，并且可以通过单次纤颤来确定。本前瞻性研究的目标是确定ULV和慢性DFT.Methods和结果之间的关系：我们研究了40例患者，3个月后，植入经静脉心脏复律除颤器。ULV定义为在T波峰值前0、20和40 msec时未能诱发纤颤的最弱双相电击。根据前瞻性定义的标准，将患者分类为临床稳定或不稳定。急性和慢性ULV（13.5 ± 5.3 J vs 12.4 ± 6.8 J，P = 0.25）和DFT（10.1 ± 5.0 J vs 9.9 ± 5.7 J，P = 0.74）的组间平均值无显著差异。5例患者（15%）被归类为不稳定。急性ULV与急性DFT的相关性（r = 0.74，P < 0.001）与慢性ULV与慢性DFT的相关性（r = 0.82，P < 0.001）相似。ULV由急性向慢性的变化与DFT相应的变化有相关性（r = 0.67，P < 0.001）。35例稳定期患者的慢性DFT均小于急性ULV +3J，但5例不稳定期患者中有2例大于急性ULV +3J（P = 0.04）。结论：慢性ULV与慢性DFT的相关性与急性ULV与急性DFT的相关性相当。ULV的时间变化预测DFT的时间变化。在临床稳定的患者中，急性ULV以上3 J的除颤安全裕度被证明是足够的慢性安全裕度。
ULV Predicts Chronic DFT.Introduction:The upper limit of vulnerability (ULV) is the shock strength at or above which ventricular fibrillation cannot be induced when delivered in the vulnerable period. It correlates acutely with the acute defibrillation threshold (DFT) and can be determined with a single episode of fibrillation. The goal of this prospective study was to determine the relationship between the ULV and the chronic DFT.Methods and Results:We studied 40 patients at, and 3 months after, implantation of transvenous cardioverter defibrillators. The ULV was defined as the weakest biphasic shock that failed to induce fibrillation when delivered 0,20, and 40 msec before the peak of the T wave. Patients were classified as clinically stable or unstable based on prospectively defined criteria. There were no significant differences between the group means for the acute and chronic determinations of ULV (13.5 ± 5.3 J vs 12.4 ± 6.8 J, P = 0.25) and DFT (10.1 ± 5.0 J vs 9.9 ± 5.7 J, P = 0.74). Five patients (15%) were classified as unstable. The strength of the correlation between acute ULV and acute DFT (r = 0.74, P < 0.001) was similar to that between the chronic ULV and chronic DFT (r = 0.82, P < 0.001). There was a correlation between the change in ULV from acute to chronic and the corresponding change in DFT (r = 0.67, P < 0.001). The chronic DFT was less than the acute ULV + 3 J in all 35 stable patients, but it was greater in 2 of 5 unstable patients (P = 0.04).Conclusions:The strength of the correlation between the chronic ULV and the chronic DFT is comparable to that between the acute ULV and the acute DFT. Temporal changes in the ULV predict temporal changes in the DFT. In clinically stable patients, a defibrillation safety margin of 3 J above the acute ULV proved an adequate chronic safety margin.