Department of Electrical Engineering, National Chin-Yi University of Technology, No. 35, Lane 215, Sec. 1, Jhongshan Rd., Taiping City, Taichung County 411, Taiwan.
Med Eng Phys. 2010 Mar;32(2):136-44. doi: 10.1016/j.medengphy.2009.11.001. Epub 2009 Nov 29.
Instead of extracting the abnormal intra-QRS potentials (AIQP) waveform, this study proposes the analysis of the unpredictable intra-QRS potentials (UIQP) based on an autoregressive moving average (ARMA) prediction model to detect the signals with sudden slope change within the QRS complex for the diagnosis of high-risk patients with ventricular tachycardia (VT). The UIQP is detected as the slope changes at slope discontinuities by the prediction error of the ARMA prediction model. Because of the linearity of the ARMA prediction model, the UIQP is also proportional to the amplitude of the QRS complex if the input QRS waves have the same shapes. Hence this study further defines the UIQP-to-QRS ratio to normalize the UIQP by the root-mean-square (RMS) value of the QRS complex. The study subjects were composed of 42 normal Taiwanese and 30 patients with sustained VT. The clinical results show that the UIQP-to-QRS ratios of the VT patients in leads X, Y and Z were significantly higher than those of the normal subjects. The logical combination of any 4 of the UIQP-to-QRS ratios and conventional time-domain parameters can increase the diagnosis performance of VT patients to 92.9% specificity, 93.3% sensitivity and 93.1% total prediction accuracy.
本研究提出了基于自回归移动平均（ARMA）预测模型分析不可预测的 QRS 内电位（UIQP），而不是提取异常的 QRS 内电位（AIQP）波形，以检测 QRS 复合体中突然斜率变化的信号，用于诊断有室性心动过速（VT）风险的高危患者。UIQP 是通过 ARMA 预测模型的预测误差检测到的，因为 ARMA 预测模型具有线性，所以如果输入 QRS 波具有相同的形状，则 UIQP 也与 QRS 复合体的幅度成比例。因此，本研究进一步定义 UIQP 与 QRS 比，通过 QRS 复合体的均方根（RMS）值对 UIQP 进行归一化。研究对象由 42 名正常台湾人和 30 名持续性 VT 患者组成。临床结果表明，VT 患者在 X、Y 和 Z 导联的 UIQP 与 QRS 比明显高于正常组。将 UIQP 与 QRS 比中的任何 4 个与传统时域参数进行逻辑组合，可以将 VT 患者的诊断性能提高到 92.9%的特异性、93.3%的敏感性和 93.1%的总预测准确性。
