This study aimed to use computer simulation method to study the mechanism of cardiac electrical activities. We optimized an electrophysiological rabbit ventricular model, including myocardial segmentation, heterogeneity and a realistic His-Purkinje network. Simulations of normal state, several types of ventricular premature contractions (VPC), conduction system pacing and right ventricular apical pacing were performed and the detailed cardiac electrical activities were studied from cell level to electrocardiogram (ECG) level. A detailed multiscale optimized ventricular model was obtained. The model effectively simulated various types of electrical activities. The synthetic ECG results were very similar to the real clinical ECG. The duration of QRS of typical VPC is 58[Formula: see text]ms, 71% longer than that of a normal-state synthetic QRS and the amplitude of the QRS is 35% larger, while the QRS duration and amplitude of the real clinical ECG of typical VPC are 69% longer and 36% larger than those of the real normal QRS. The duration of QRS of ventricular fusion beat is 31[Formula: see text]ms, 91% of that of a normal-state synthetic QRS and the amplitude of the QRS is 36% larger, while the QRS duration of the real clinical ECG of a ventricular fusion beat is 92% of the real normal QRS and the amplitude is 37% larger. Therefore, the results indicate that this model is effective and reliable in studying the detailed process of cardiac excitation and pacing.

中文翻译：

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兔心室电生理模型优化及合成心电图模拟

本研究旨在利用计算机模拟方法研究心脏电活动的机制。我们优化了电生理兔心室模型，包括心肌分割、异质性和逼真的 His-Purkinje 网络。对正常状态、几种类型的室性早搏 (VPC)、传导系统起搏和右心室心尖起搏进行了模拟，并从细胞水平到心电图 (ECG) 水平研究了详细的心脏电活动。获得了详细的多尺度优化心室模型。该模型有效地模拟了各种类型的电活动。合成心电图结果与真实临床心电图非常相似。典型VPC的QRS时长为58[公式：见正文]ms，比正常状态合成 QRS 长 71%，QRS 波幅大 35%，而典型 VPC 真实临床心电图的 QRS 持续时间和幅值比真实心电图长 69%，大 36%正常 QRS。心室融合搏动QRS时长为31[公式：见正文]ms，是正常状态合成QRS的91%，QRS波幅大36%，而真实临床心电图QRS时长为心室融合搏动是真实正常 QRS 的 92%，幅度大 37%。因此，结果表明该模型在研究心脏兴奋和起搏的详细过程方面是有效和可靠的。而典型VPC的真实临床心电图QRS时长和幅度比真实正常QRS长69%，大36%。心室融合搏动QRS时长为31[公式：见正文]ms，是正常状态合成QRS的91%，QRS波幅大36%，而真实临床心电图QRS时长为心室融合搏动是真实正常 QRS 的 92%，幅度大 37%。因此，结果表明该模型在研究心脏兴奋和起搏的详细过程方面是有效和可靠的。而典型VPC的真实临床心电图QRS时长和幅度比真实正常QRS长69%，大36%。心室融合搏动QRS时长为31[公式：见正文]ms，是正常状态合成QRS的91%，QRS波幅大36%，而真实临床心电图QRS时长为心室融合搏动是真实正常 QRS 的 92%，幅度大 37%。因此，结果表明该模型在研究心脏兴奋和起搏的详细过程方面是有效和可靠的。心室融合搏动的真实临床心电图QRS时限为真实正常QRS的92%，幅度增大37%。因此，结果表明该模型在研究心脏兴奋和起搏的详细过程方面是有效和可靠的。心室融合搏动的真实临床心电图QRS时限为真实正常QRS的92%，幅度增大37%。因此，结果表明该模型在研究心脏兴奋和起搏的详细过程方面是有效和可靠的。