Introduction: Detailed global maps of atrial electrical activity are needed to understand mechanisms of atrial rhythm disturbance in small animal models of heart disease. To date, optical mapping systems have not provided enough spatial resolution across sufficiently extensive regions of intact atrial preparations to achieve this goal. Objectives: To develop an integrated platform for quantifying regional electrical properties and analyzing reentrant arrhythmia in a bi-atrial preparation. Methods: Intact atria from 6/7 months old female spontaneously hypertensive rats (N=6) were isolated and secured in a constant flow superfusion chamber at 37°C. Optical mapping was performed with the membrane-voltage dye di-4 ANEPPS using LED excitation and a sCMOS camera. Programmed stimulus trains were applied from RA and LA sites to assess rate-dependent electrical behavior and to induce atrial arrhythmia. Signal-to-noise ratio was improved by sequential processing steps that included spatial smoothing, temporal filtering and, in stable rhythms, ensemble-averaging. Results: Activation time, repolarization time and action potential duration (APD) maps were constructed at high spatial resolution for a wide range of coupling intervals. These data were highly consistent within and between experiments. They confirmed preferential atrial conduction pathways and demonstrated distinct medial-to-lateral APD gradients. We also showed that reentrant arrhythmias induced in this preparation were explained by the spatial variation of these electrical properties. Conclusion: Our new methodology provides a robust means of 1) quantifying regional electrical properties in the intact rat atria at higher spatio-temporal resolution than previously reported, and 2) characterizing reentrant arrhythmia and analyzing mechanisms that give rise to it.

中文翻译：

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一种用于绘制局部电特性和表征孤立的完整大鼠心房中的心律失常的新系统

简介：需要详细的心房电活动全局图来了解心脏病小动物模型中心房节律紊乱的机制。迄今为止，光学标测系统还没有在足够广泛的完整心房准备区域提供足够的空间分辨率来实现这一目标。目标：开发一个综合平台，用于量化区域电特性和分析双心房准备中的折返性心律失常。方法：将 6/7 个月大的雌性自发性高血压大鼠（N=6）的完整心房分离并固定在 37°C 的恒流灌注室中。使用 LED 激发和 sCMOS 相机使用膜电压染料 di-4 ANEPPS 进行光学映射。从 RA 和 LA 站点应用程序化刺激序列来评估依赖于速率的电行为并诱发房性心律失常。信噪比通过连续处理步骤得到改善，包括空间平滑、时间滤波以及稳定节奏中的整体平均。结果：激活时间、复极时间和动作电位持续时间 (APD) 图以高空间分辨率构建，用于广泛的耦合间隔。这些数据在实验内和实验之间高度一致。他们证实了优先心房传导通路，并证明了不同的内侧到外侧 APD 梯度。我们还表明，这些电特性的空间变化可以解释这种制备过程中诱发的折返性心律失常。结论：