Department of Information Engineering, Polytechnic University of Marche, Ancona, Italy.
Med Eng Phys. 2012 Apr;34(3):305-12. doi: 10.1016/j.medengphy.2011.07.019. Epub 2011 Aug 10.
An association between heterogeneity of repolarization alternans (RA) and cardiac electrical instability has been reported. Characterization of RA in health and identification of physiological RA heterogeneity may help discrimination of abnormal RA cases more likely associated to arrhythmic events. Thus, aim of the present study was the identification of a physiological RA region in terms of mean temporal location (MRAD) with respect to the T apex, and mean amplitude (MRAA), by application of our heart-rate adaptive match filter method to clinical ECG recordings from 51 control healthy (CH) subjects and 43 acute myocardial infarction (AMI) patients. Results indicate that RA occurring within the first half of the T wave is dominant in both CH and AMI populations (74.5% and 53.5% of cases, respectively; P<0.05). Definition of physiological RA region in the MRAD vs. MRAA plane (-83 ms ≤ MRAD ≤ 23 ms, 0≤ MRAA ≤ 30 μV) provided 0% and 32.6% abnormal RA cases among the CH subjects and AMI patients, respectively. We conclude that myocardial infarction may associate with an RA occurring early (MRAD<-83 ms) or late (MRAD >23 ms) along the JT segment, in addition or in alternative to an abnormally high RA amplitude (MRAA >30 μV).
已有研究报道，复极离散度（RA）的异质性与心脏电不稳定性之间存在关联。在健康人群中对 RA 进行特征描述，并识别生理性 RA 异质性，可能有助于区分更可能与心律失常事件相关的异常 RA 病例。因此，本研究旨在通过应用我们的心率自适应匹配滤波器方法，从 51 名健康对照（CH）受试者和 43 名急性心肌梗死（AMI）患者的临床心电图记录中，确定 T 波顶点的平均时间位置（MRAD）和平均幅度（MRAA）的生理性 RA 区域。结果表明，在 CH 和 AMI 人群中，T 波前半段的 RA 占主导地位（分别为 74.5%和 53.5%；P<0.05）。在 MRAD 与 MRAA 平面上定义生理性 RA 区域（-83 ms≤MRAD≤23 ms，0≤MRAA≤30 μV），在 CH 受试者和 AMI 患者中，分别有 0%和 32.6%的异常 RA 病例。我们的结论是，心肌梗死可能与沿 JT 段的早期（MRAD<-83 ms）或晚期（MRAD >23 ms）RA 有关，或者与异常高的 RA 幅度（MRAA >30 μV）有关。
