Fixed complex electrograms during sinus rhythm and local pacing: potential ablation targets for persistent atrial...

Area of Science:

• Electrophysiology
• Cardiology
• Medical Diagnostics

Background:

• Complex electrograms during sinus rhythm (C-EGMs) in atrial fibrillation (AF) patients can be pathological or normal.
• Distinguishing between pathological and non-pathological C-EGMs is crucial for effective treatment.

Purpose of the Study:

• To determine if local pacing can differentiate pathological C-EGMs in patients with persistent AF.
• To assess the clinical significance and impact on ablation outcomes of fixed C-EGMs.

Main Methods:

• Left atrial mapping during sinus rhythm was performed in 126 persistent AF patients and 27 patients with left-side accessory pathway (LAP).
• Local pacing was used to classify C-EGMs as fixed (unchanged by pacing) or non-fixed (normalized by pacing).
• Outcomes of ablation strategies targeting fixed C-EGMs versus linear ablation were compared.

Main Results:

• Fixed C-EGMs were significantly more prevalent in persistent AF patients compared to LAP patients (P < 0.01).
• Fixed C-EGMs exhibited lower amplitudes, longer durations, and longer Stimuli-P wave intervals than non-fixed C-EGMs.
• Ablation of fixed C-EGMs, compared to linear ablation, reduced AF recurrence (HR: 0.43; P = 0.011).

Conclusions:

• Local pacing effectively classifies C-EGMs into fixed and non-fixed types.
• Fixed C-EGMs likely represent abnormal atrial substrates and are associated with improved ablation outcomes when specifically targeted.
• Targeted ablation of fixed C-EGMs improves outcomes in persistent AF patients.