Two dimensional wavelet energy analysis on a beat to beat basis: application to Atrial Fibrillation

Area of Science:

• Cardiology
• Biomedical Engineering
• Electrophysiology

Background:

• Atrial Fibrillation (AF) originates from ectopic sources, frequently in Pulmonary Veins (PVs).
• PV isolation is a surgical intervention to mitigate AF triggers.
• Understanding atrial substrate changes post-ablation is crucial for AF management.

Purpose of the Study:

• To investigate P-wave morphology and dynamics after PV isolation.
• To analyze the impact of ablation on potentially arrhythmogenic tissue in PVs.
• To correlate electrophysiological changes with RR intervals.

Main Methods:

• Vectrocardiography recordings from 20 patients before and after PV isolation.
• Two-dimensional wavelet energy analysis across five frequency bands.
• Extraction of features like ellipse axes and center of mass from energy plots.

Main Results:

• Significant differences in P-wave analysis were observed between pre- and post-ablation groups.
• Wavelet energy patterns showed distinct changes correlating with RR intervals.
• Statistical analysis indicated a shift towards a more stable atrial electrical conduction.

Conclusions:

• PV isolation significantly alters atrial electrophysiology.
• The study demonstrates a more stable atrial substrate following ablation.
• This provides insights into the mechanisms underlying AF recurrence and management.