A beat-to-beat P wave analysis in healthy population

Aim of this study is to explore and quantify possible beat-to-beat variations in P wave characteristics. Two-minute X-lead ECG recordings were analyzed. Data were obtained from Physionet database. Each P wave was fitted by a Gaussian function whose parameter variations were investigated over two minutes window. The normalized root mean squared error (NRMSE) between each P wave and its fitting was computed. To evaluate the variability of the estimated parameters, the coefficient of variation (CV) was computed. The proposed model well fitted the P waves, being the mean NRMSE 0.047 ± 0.030 mV (range 0.012 - 0.140 mV). A variability was found in all patients for both the parameters A and s, reflecting P waves amplitude and duration, respectively, being CVA 0.087 ± 0.050 mV (range 0.032 - 0.253 mV) and CV_σ 0.093 ± 0.053 (range 0.028 - 0.27). These preliminary results could be used as a starting point for future beat-to-beat P wave analysis in patients with atrial conduction pathologies.