Ryerson University, Toronto, Ontario, Canada.
Heart Rhythm. 2011 May;8(5):740-9. doi: 10.1016/j.hrthm.2010.12.033. Epub 2010 Dec 24.
Effective chest compressions during prolonged ventricular fibrillation (VF) have been shown to increase the chances of successful defibrillation to a rhythm associated with a sustainable cardiac output. There is currently no effective method of recording the degree of antegrade coronary artery flow during chest compression in VF.
This study sought to quantify the relationship between the antegrade coronary flow and the characteristics of human VF using near real-time wavelet-based electrocardiographic markers.
VF experiments were conducted in 8 isolated human hearts. The Langendorff perfusion enabled different flow rates (perfusion) during VF, which allowed for the simulation of chest compression with different efficacies. After the initiation of VF, the hearts were maintained in ischemia (no flow) for 3 minutes, followed by a 2-minute reperfusion and defibrillation. The experiments were repeated at flows of 0%, 30%, and 100% of baseline perfusion, and volume-conducted surface electrograms were recorded and analyzed using continuous wavelet transform in 5-second frames.
Near real-time wavelet features were derived that demonstrated significant differences in the multicomponent nature of VF signals and predicted perfusion rate characteristics for different flow rates (i.e., 0%, 30%, and 100%; P < .0006). A pattern classifier was trained using the feature values from 5 hearts, and the flow rates for 3 additional hearts were predicted with an accuracy of 90%.
VF electrogram characteristics as measured by wavelet analysis relate to antegrade coronary flow rate during VF. These findings suggest that chest compression efficacy of physiological importance could be monitored using near real-time wavelet analysis.
在长时间室颤（VF）期间进行有效的胸部按压已被证明可增加除颤成功的机会，从而恢复与可持续心输出量相关的节律。目前，尚无在 VF 期间记录冠状动脉前向血流程度的有效方法。
本研究旨在使用实时小波心电图标记物定量分析前向冠状动脉血流与人类 VF 特征之间的关系。
在 8 个离体人心肌中进行 VF 实验。Langendorff 灌注允许在 VF 期间进行不同的血流速度（灌注），从而模拟了不同效果的胸部按压。VF 发作后，心脏在缺血（无血流）状态下维持 3 分钟，然后进行 2 分钟的再灌注和除颤。在 0%、30%和 100%基础灌注流量下重复进行实验，并使用连续小波变换在 5 秒帧内记录和分析容积传导表面心电图。
得出了实时小波特征，这些特征表明 VF 信号的多分量性质存在显著差异，并预测了不同流量（即 0%、30%和 100%）的灌注率特征（P<0.0006）。使用 5 个心脏的特征值训练模式分类器，并以 90%的准确度预测了另外 3 个心脏的流量。
小波分析测量的 VF 心电图特征与 VF 期间的前向冠状动脉血流速率相关。这些发现表明，使用实时小波分析可以监测具有生理重要性的胸部按压效果。
