Age and sex differences in the P-wave signal-averaged electrocardiogram in a Japanese study population

Normal P wave signal-averaged electrocardiogram (SAE) values were determined in 120 healthy Japanese adults (56 men, 64 women), aged 44.5+/-10.2 years (mean+/-SD). The P wave trigger method was used with a Fukuda FDX6500 recorder. We used bipolar Frank leads (X,Y,Z), and recordings were made with forward and backward digital Butterworth filters [40 Hz (18 dB / oct) - 300 Hz (12 dB / oct)]. The recordings were taken for the following five parameters: forward and backward filtered P wave duration [fPd (F); tPd (B)]; bidirectionally corrected fPd [tPd (C)]; and 20 ms of the terminal portions of voltage at forward and backward filtering (RMS20). Overall, fPd (F) was 117.8-136.4 ms, fPd (B) 116.4-134.4 ms, fPd (C) 97.4-115.2 ms, RMS20 (F) 1.6-3.6 microV, and RMS20 (B) was 2.2-5.4 microV. Between the sexes, there were significant differences in fPd (F) (p<0.001) and fPd (B) (p<0.01) and in RMS20 (F) (p<0.05) and RMS20 (B) (p<0.05). Weak positive correlations were observed between fPd (F) and body surface area, fPd (F) and age, fPd (B) and body surface area, fPd (B) and age, fPd (C) and body surface area, and fPd (C) and age. There was no evident correlation, however, between either forward or backward RMS20 and body surface area or between forward or backward RMS20 and age. Differences in the normal P wave values between the sexes and age groups were evaluated in this study.