Epicardial mapping of ventricular defibrillation with monophasic and biphasic shocks in dogs.
Epicardial mapping of ventricular defibrillation with monophasic and biphasic shocks in dogs.
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DOI：
10.1161/01.res.72.1.145
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发表时间：
1993
影响因子：
20.1
通讯作者：
Xiaohong Zhou;James P. Daubert;Patrick D. Wolf;William M. Smith;R. Ideker
中科院分区：
文献类型：
--
作者：
Xiaohong Zhou;James P. Daubert;Patrick D. Wolf;William M. Smith;R. Ideker
为了研究除颤机制和双相波形除颤效率增加的原因，分四步逐步降低15只犬右心室32 x 30 mm区域的电位梯度，同时在心室肌的其余部分保持强电位梯度场。斑块下方的右心室体积为总心室质量的10 ± 2%。通过左心室尖部和右心房上的电极给予除颤阈值电压以上30%的10毫秒双相（8只犬）或5/5毫秒双相（7只犬）截短指数电击，以产生强电位梯度场。同时，通过小右心室区域两侧的网状电极给予波形相同但极性相反的较弱电击，以消除该区域的部分电位差，并产生四级电位梯度场之一。从小区域的117个心外膜电极记录电击电位和激活，并且在一只狗中，从包含72个电极的袜子记录全局心外膜激活和电位。在10秒的电诱导纤颤后，对每个梯度场进行10次成功除颤测试。对于单相和双相电击，成功除颤尝试的百分比随着小区域电位梯度的降低而降低（p < 0.05）。对于单相电击，平均+/- SD电位梯度为5.4 +/- 0.8 V/cm，对于双相电击，平均+/- SD电位梯度为2.7 +/- 0.3 V/cm，除颤成功率约为80%（p < 0.05）。当梯度大于5V/cm时，8个波形的小区域均未出现后激活锋。对于这两种波形，postshock激活前的冲击后，显着不同的冲击前，表现出无论是局灶性起源或单向传导。（400字处截断摘要）
To study the mechanism of defibrillation and the reason for the increased defibrillation efficacy of biphasic waveforms, the potential gradient in a 32 x 30-mm region of the right ventricle in 15 dogs was progressively lowered in four steps while a strong potential gradient field was maintained throughout the rest of the ventricular myocardium. The volume of right ventricle beneath the plaque was 10 +/- 2% of the total ventricular mass. A 10-msec monophasic (eight dogs) or 5/5-msec biphasic (seven dogs) truncated exponential shock 30% above the defibrillation threshold voltage was given via electrodes on the left ventricular apex and right atrium to create the strong potential gradient field. Simultaneously, a weaker shock with the same waveform but opposite polarity was given via mesh electrodes on either side of the small right ventricular region to cancel part of the potential difference in the region and to create one of the four levels of potential gradient fields. Shock potentials and activations were recorded from 117 epicardial electrodes in the small region, and in one dog global epicardial activations and potentials were recorded from a sock containing 72 electrodes. Each gradient field was tested 10 times for successful defibrillation after 10 seconds of electrically induced fibrillation. For both monophasic and biphasic shocks, the percentage of successful defibrillation attempts decreased (p < 0.05) as the potential gradient decreased in the small region. Defibrillation was successful approximately 80% of the time for a mean +/- SD potential gradient of 5.4 +/- 0.8 V/cm for monophasic shocks and 2.7 +/- 0.3 V/cm for biphasic shocks (p < 0.05). No postshock activation fronts arose from the small region for eight waveform when the gradient was more than 5 V/cm. For both waveforms, the postshock activation fronts after the shocks were markedly different from those just before the shock and exhibited either a focal origin or unidirectional conduction.(ABSTRACT TRUNCATED AT 400 WORDS)