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Hierarchical Schema for Identifying Focal Electrical Sources During Human Atrial Fibrillation: Implications for
Sigfus Gizurarson1, Rupin Dalvi1, Moloy Das1
1Peter Munk Cardiac Center, University Health Network, Toronto, Canada.
JACC. Clinical Electrophysiology
|May 16, 2018
Summary
This study identified focal sources (FS) of atrial fibrillation (AF) using periodic component analysis (PiCA) and electrogram (EGM) morphology. Identifying these FS, particularly those outside the pulmonary veins, is crucial for effective AF ablation and reducing recurrence.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Atrial fibrillation (AF) management remains challenging, with difficulties in localizing focal sources (FS) responsible for maintaining the arrhythmia.
- Conventional time-frequency analysis methods have limitations in accurately identifying these critical FS.
- Accurate FS localization is essential for guiding substrate ablation strategies to improve AF treatment outcomes.
Purpose of the Study:
- To develop and validate a novel method for localizing focal sources (FS) during atrial fibrillation (AF).
- To utilize periodic component analysis (PiCA) and unipolar electrogram (EGM) morphology to identify FS.
- To assess the correlation between identified FS and AF recurrence after ablation.
Main Methods:
- Bipolar electrograms (EGMs) were recorded from the left atrium (LA) in 41 AF patients using a 20-pole catheter.
- Periodic component analysis (PiCA) was employed to identify periodic EGMs.
- Focal sources (FS) were defined as periodic sites exhibiting predominantly QS unipolar EGM morphology.
Main Results:
- Focal sources (FS) were identified in 63% of patients, with a mean of 1.5 ± 1.5 in the pulmonary veins (PV) and 2.6 ± 2.3 extra-PV.
- Patients with AF recurrence had a shorter mean global LA periodicity cycle length (143 ± 20 ms) compared to those without (154 ± 9 ms).
- Exclusively PV FS were associated with a low recurrence rate (8%), while extra-PV FS showed a significantly higher recurrence rate (50%).
Conclusions:
- A novel hierarchical analysis combining PiCA and unipolar EGM morphology effectively detected a limited number of FS in persistent AF patients.
- Focal sources (FS) located within the pulmonary veins (PV) were linked to successful PV antral ablation outcomes.
- Further prospective research is warranted to confirm the role of these identified FS in maintaining AF and their utility as ablation targets.
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