The Consistency of Filtered P-Wave Duration among Different Electrocardiogram Instruments

Abstract

Background: Filtered P-wave duration (fPWD) is used to estimate the severity of atrial remodeling associated with atrial fibrillation (AF). However, the consistency of fPWD measured by different ECG instruments has never been determined. The aim of this study is to compare fPWDs measured by FCP-7541 (Fukuda Denshi) and MAC5500 (GE Medical Systems). Methods: We enrolled 62 subjects (25 healthy adults and 37 non-valuvular paroxysmal AF patients). Signal averaged ECG was performed twice sequentially using 2 different ECG instruments, FCP-7541 installed with FP-705LP and MAC5500 with P Hi-Res. The P-wave signals were recorded from bipolar X, Y and Z leads until the noise amplitude reduced to 0.3 µV. Forward and backward Butterworth filter (40–300 Hz) was used in FCP-7541 and fast Fourier transform (FFT) filter (40–250 Hz) was applied in MAC5500. The filtered signals were combined into a vector magnitude of the P-wave. Results: Significant correlations between fPWDs by these 2 different instruments were observed (r=0.85, p<0.0001). However, fPWD measured by FCP7541 was significantly shorter than that by MAC5500 (129±13 vs. 121±13 ms, p<0.0001). Conclusion: Though there was an excellent correlation between the values of fPWD evaluated by FCP-7541 and those by MAC5500, those by FCP7541 were a little shorter than those by MAC5500. The interpretation of fPWD should be done with an understanding of possible difference between different ECG instruments.