P-wave complexity in normal subjects and computer models

Background: P waves reported in electrocardiology literature uniformly appear smooth. Computer simulation and signal analysis studies have shown much more complex shapes. Objective: We systematically investigated P-wave complexity in normal volunteers using high-fidelity electrocardiographic techniques without filtering. Methods: We recorded 5-min multichannel ECGs in 16 healthy volunteers. Noise and interference were reduced by averaging over 300 beats per recording. In addition, normal P waves were simulated with a realistic model of the human atria. Results: Measured P waves had an average of 4.1 peaks (range 1–10) that were reproducible between recordings. Simulated P waves demonstrated similar complexity, which was related to structural discontinuities in the computer model of the atria. Conclusion: The true shape of the P wave is very irregular and is best seen in ECGs averaged over many beats.Optimization of noninvasive assessment of the substrate for atrial fibrillationThe European Network for Translational Research in Atrial Fibrillatio