Different from the traditional methods of assessing the cardiac activities through heart rhythm statistics or P-QRS-T complexes separately, this study demonstrates their interactive effects on the power density spectrum (PDS) of ECG signal with applications for the diagnosis of ST-segment elevation myocardial infarction (STEMI) diseases. Firstly, a mathematical model of the PDS of ECG signal with a random pacing pulse train (PPT) mimicking S-A node firings was derived. Secondly, an experimental PDS analysis was performed on clinical ECG signals from 49 STEMI patients and 42 healthy subjects in PTB Diagnostic Database. It was found that besides the interactive effects which are consistent between theoretical and experimental results, the ECG PDSs of STEMI patients exhibited consistently significant power shift towards lower frequency range in ST-elevated leads in comparison with those of reference leads and leads of health subjects with the highest median frequency shift ratios at 51.39 ± 12.94% found in anterior MI. Thirdly, the results of ECG simulation with systematic changes in PPT firing statistics over various lengths of ECG data ranging from 10 s to 60 mins revealed that the mean and median frequency parameters were less affected by the heart rhythm statistics and the data length but more depended on the alterations of P-QRS-T complexes, which were further confirmed on 33 more STEMI patients in European ST-T Database, demonstrating that the frequency indexes could be potentially used as alternative indicators for STEMI diagnosis even with ultra-short-term ECG recordings suitable for wearable and mobile health applications in living-free environments.

中文翻译：

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HRV 和 P-QRS-T 对心电信号功率密度谱的交互影响


与单独通过心律统计或P-QRS-T复合波评估心脏活动的传统方法不同，本研究展示了它们对心电信号功率密度谱（PDS）的交互影响以及在ST段抬高诊断中的应用心肌梗塞（STEMI）疾病。首先，推导了具有模仿 SA 节点放电的随机起搏脉冲串 (PPT) 的 ECG 信号 PDS 的数学模型。其次，对 PTB 诊断数据库中 49 名 STEMI 患者和 42 名健康受试者的临床心电信号进行实验性 PDS 分析。结果发现，除了理论结果与实验结果一致的交互作用外，与参考导联和健康受试者导联相比，STEMI 患者的心电图 PDS 在 ST 抬高导联中表现出一致的显着功率向较低频率范围偏移。前部 MI 中的最高中位频移比为 51.39 ± 12.94%。第三，心电图模拟的结果显示，在10秒到60分钟的不同长度的心电图数据上，PPT放电统计数据发生系统变化，平均频率和中频参数受心律统计数据和数据长度的影响较小，但更多地依赖于心电图数据。 P-QRS-T 复合波的改变，在欧洲 ST-T 数据库中的另外 33 名 STEMI 患者中得到进一步证实，表明即使在超短期心电图的情况下，频率指数也有可能用作 STEMI 诊断的替代指标适用于自由生活环境中的可穿戴和移动健康应用的录音。