Porta A, Baselli G, Lombardi F, Cerutti S, Antolini R, Del Greco M, Ravelli F, Nollo G
Dipartimento di Bioingegneria, Politecnico di Milano, Italia.
Med Biol Eng Comput. 1998 Jan;36(1):35-42. doi: 10.1007/BF02522855.
Three automatic approaches to ventricular repolarisation duration measurement (R-Tapex, R-T(end threshold) and R-T(end fitting) methods) are compared on computer-generated and real ECG signals, in relation to their reliability in the presence of the most common electrocardiographic artefacts (i.e. additive broadband noise and additive and multiplicative periodical disturbances). Simulations permit the evaluation of the amount of R-T beat-to-beat variability induced by the artefacts. The R-T(end threshold) method performs better than the R-T(end fitting) one, and, hence, the latter should be used with caution when R-T(end) variability is addressed. Whereas the R-Tapex method is more robust with regard to broadband noise than the R-T(end threshold) one, the reverse situation is observed in the presence of periodical amplitude modulations. A high level of broadband noise dose not prevent the detection of the central frequency of underlying R-T periodical changes. Comparison between the power spectra of the beat-to-beat R-T variability series obtained from three orthogonal ECG leads (X,Y,Z) is used to assess the amount of real and artefactual variability in 13 normal subjects at rest. The R-Tapex series displays rhythms at high frequency (HF) with a percentage power on the Z lead (57.1 +/- 4.9) greater than that on the X and Y leads (41.9 +/- 4.6 and 46.1 +/- 4.9, respectively), probably because of respiratory-related artefacts affecting the Z lead more remarkably. More uniform HF power distributions over X,Y,Z leads are observed in the R-T(end threshold) series (31.8 +/- 3.8, 39.2 +/- 4.1 and 35.1 +/- 4.2, respectively), thus suggesting minor sensitivity of the R-T(end threshold) measure to respiratory-related artefacts.
在计算机生成的和真实的心电图信号上，对三种测量心室复极持续时间的自动方法（R-Tapex、R-T（结束阈值）和R-T（结束拟合）方法）进行了比较，涉及它们在存在最常见的心电图伪迹（即加性宽带噪声以及加性和乘性周期性干扰）时的可靠性。模拟允许评估由伪迹引起的逐搏R-T变异性的量。R-T（结束阈值）方法比R-T（结束拟合）方法表现更好，因此，在处理R-T（结束）变异性时应谨慎使用后者。虽然R-Tapex方法在宽带噪声方面比R-T（结束阈值）方法更稳健，但在存在周期性幅度调制时情况相反。高水平的宽带噪声并不妨碍检测潜在R-T周期性变化的中心频率。通过比较从三个正交心电图导联（X、Y、Z）获得的逐搏R-T变异性系列的功率谱，来评估13名静息正常受试者中真实和伪迹变异性的量。R-Tapex系列在高频（HF）显示节律，Z导联上的功率百分比（57.1±4.9）大于X和Y导联上的（分别为41.9±4.6和46.1±4.9），这可能是因为与呼吸相关的伪迹对Z导联的影响更显著。在R-T（结束阈值）系列中观察到X、Y、Z导联上的HF功率分布更均匀（分别为31.8±3.8、39.2±4.1和35.1±4.2），因此表明R-T（结束阈值）测量对与呼吸相关的伪迹的敏感性较小。
