P-Wave Morphological Variability Exacerbation Prior to Atrial Fibrillation Episodes

Maikel Noriega1, Alba Martin2, Aleksei Savelev3, Pyotr Platonov4, Javier Marta5, Monika Butkuvienė6, Juan Pablo Martí­nez7, Pablo Laguna8
1UNIZAR, 2Biomedical Signal Interpretation and Computational Simulation Group (BSICoS), Universidad de Zaragoza, 3St. Petersburg State University, 4Lund University, 5Universitary Hospital Miguel Servet, 6Biomedical Engineering Institute, Kaunas University of Technology, 7jpmart@unizar.es, 8Zaragoza University


Abstract

Maikel Noriega, Alba Martín-Yebra, Aleksei Savelev, Pyotr Platonov, Javier Marta, Monika Butkuviene, Juan Pablo Martínez, Pablo Laguna

BSICoS-I3A, Zaragoza University; CIBER-BBN, Zaragoza, Spain

Introduction: P-wave morphological variability (PWMV) has been shown to be a marker of atrial electrical instability and may reflect instabilities that precede atrial fibrillation (AF). This study analyzes the temporal evolution of PWMV in sinus rhythm during the hour prior to AF onset characterizing changes in PWMV, potentially signaling a vulnerable atrial substrate, and identifying significant turning times preceding the AF episodes onset.

Methods: We analyzed 32 ambulatory ECG recordings from subjects with paroxysmal AF (mean[range] duration: 104[21–156] hours). For each i-th subject and j-th AF episode, the one-hour, pre-AF PWMV is characterized in consecutive k-th 2-min windows, as: 1) the median absolute deviation (MAD) of the beat P waves is computed 2) the ratio of this median energy to the median of the P wave energy in each subject, is computed and 3) The subject median across AF episodes, is computed as well and the median across patients, characterizing the cohort PWMV dynamics. A two-segment linear function fit by least squares error (LSE) minimization, is used to quantify the cohort dynamics. For technical details see pdf abstract.

Results: In 56% of patients the MAD energy ratio tracings present noticeable higher values in the last 30 min before AF event. Analyzing the cohort dynamic of the ratio, we observe that it remains relatively stable until 8 minutes before the AF episode, when its value starts increasing, see Figure 1 in pdf abstract.

Conclusion: P-wave morphological variability can be monitored by quantified their short-time MAD relative energy, showing an increasing P wave morphological variability trend from 8 minutes before AF onset.