Conduction Disorders during Sinus Rhythm in Relation to Atrial Fibrillation Persistence

Area of Science:

• Cardiology
• Electrophysiology
• Medical Imaging

Background:

• Current atrial fibrillation (AF) classification relies on clinical factors, lacking objective electrophysiological markers.
• An objective, substrate-based classification of AF could improve patient management and treatment strategies.

Purpose of the Study:

• To quantify atrial conduction parameters during sinus rhythm (SR) using epicardial mapping.
• To correlate these electrophysiological parameters with clinical AF classifications and progression predictors.

Main Methods:

• Intra-operative high-resolution epicardial mapping was used to assess atrial conduction during SR.
• Patients were stratified by clinical AF classification, spontaneous AF termination, and P-wave duration.
• HATCH scores and interatrial block were evaluated.

Main Results:

• Conduction delays, particularly at Bachmann's bundle (BB), were observed in persistent AF patients and those without spontaneous AF termination.
• Longer BB activation times correlated with higher HATCH scores and P-wave duration ≥ 120 ms.
• ROC curve analysis indicated limited discriminatory power of the assessed electrophysiological parameters.

Conclusions:

• Clinical AF classifications may not fully capture underlying electrophysiological substrate.
• Further research is necessary to develop an objective, electrophysiology-based classification system for AF.