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利用单相动作电位 (MAP)技术描述一种在电压范围内测量心室复极空间离散的新方法。 10个均匀分布的MAP电极 ( 2个位于心内膜、8个位于心外膜 )在 8只离体Langendorff灌流兔心脏上同步记录MAP信号。电压范围的复极离散定义为 3相复极期间某一时刻不同部位MAP复极百分比最大与最小值之差。每隔 10ms计算一次电压离散值并以此构建离散曲线。结果 :将测得的复极离散值对复极时间作图得到一条离散曲线 ,其特点为 :离散在复极早期呈逐渐增加的趋势 ,达到峰值后开始下降 ,并在复极晚期降至趋向于零。为检测此方法的实用性 ,我们比较了离散曲线与双相T波电击易损窗的关系后发现 ,易损窗占绝对优势地发生在离散值高的时候 ,并且曲线的峰值与易损窗的左沿密切相关 (r=0 .95 ,P <0 .0 1)。另外 ,心肌缺血使离散曲线高度增加 ,峰值左移 ,同时易损窗的宽度增加。结论 :电压范围的复极离散可为我们提供一种新的测量复极非均一性的手段 ,从而有助于更好地理解心律失常易感性
A single phase action potential (MAP) technique was used to describe a new method for measuring ventricular repolarization dispersion in the voltage range. Ten uniformly distributed MAP electrodes (two in the endocardium and eight in the epicardium) were used to simultaneously record MAP signals on eight isolated Langendorff-perfused rabbit hearts. The repolarization dispersion in the voltage range is defined as the difference between the maximum and minimum percentages of MAP repolarization at different points during a 3-phase repolarization. The voltage dispersion is calculated every 10 ms and the discrete curve is constructed. Results: The measured plots of repolarization versus repolarization time obtained a discrete curve, which was characterized by the fact that the dispersion tended to increase gradually during the early period of repolarization, and then began to decline after reaching the peak value and then decreased to the trend of late repolarization At zero. In order to test the practicability of this method, we compared the relation between the discrete curve and the vulnerability of TWT shockwaves and found that the vulnerable window takes the absolute advantage when the discrete value is high, and the peak value of the curve and the vulnerable window The left edge is closely related (r = 0.95, P <0.01). In addition, myocardial ischemia increased the discrete curve height, the peak left, while increasing the width of vulnerable window. Conclusion: The bipolar dispersion of the voltage range provides us with a new means of measuring repolarization heterogeneity, which helps to better understand the risk of arrhythmia