Dominant frequency differences in atrial fibrillation patients with and without left ventricular systolic dysfunction

Area of Science:

• Cardiology
• Electrophysiology
• Medical Physics

Background:

• Atrial fibrillation (AF) is a complex arrhythmia.
• Left ventricular systolic dysfunction (LVSD) can influence AF mechanisms.
• Understanding AF drivers is crucial for effective treatment.

Purpose of the Study:

• To investigate the mechanisms underlying AF in patients with LVSD.
• To compare dominant frequency (DF) spatiotemporal stability in different AF types and LVSD presence.
• To elucidate the role of stable arrhythmia sources in persistent AF (PEAF) versus paroxysmal AF (PAAF).

Main Methods:

• Studied dominant frequency (DF) spatiotemporal stability in 15 PEAF with LVSD (Group I), 15 PEAF without LVSD (Group II), and 10 PAAF without LVSD (Group III).
• Analyzed DF at 536 sites at baseline (DF1) and after 26 ± 12 minutes (DF2).
• Assessed DF differences and spatial gradients across various left atrial regions.

Main Results:

• A DF1-DF2 difference ≤0.5 Hz was observed in 77% (Group I), 70% (Group II), and 48% (Group III) of sites (P < 0.001).
• Maximal DF1 and DF2 occurred at the same site in 12/15 (Group I), 11/15 (Group II), and 0/10 patients (Group III) (P < 0.01).
• Group I showed higher DFs at the left atrial appendage (LAA) compared to other regions; Group III had higher DF at the pulmonary vein-left atrial junction (PV-LAJ).

Conclusions:

• Dominant frequency stability supports stable arrhythmia sources as the mechanism for PEAF, both with and without LVSD.
• This stability was not evident in PAAF, suggesting different underlying mechanisms.
• Findings highlight distinct electrophysiological characteristics between persistent and paroxysmal AF, particularly in the context of LVSD.