Comparative Study of Methods for Cycle Length Estimation in Fractionated Electrograms of Atrial Fibrillation

Area of Science:

• Biomedical Engineering
• Cardiac Electrophysiology
• Medical Device Technology

Background:

• Atrial cycle length (CL) analysis is crucial for catheter ablation (CA) of atrial fibrillation (AF).
• Accurate detection of local activation waves (LAWs) is essential for reliable CL estimation but remains challenging, especially with fractionated electrograms (EGMs).
• Existing LAW detection methods require evaluation for their performance in CL estimation under various EGM fractionation levels.

Purpose of the Study:

• To compare the performance of three distinct LAW detection methods in estimating atrial cycle length (CL).
• To evaluate method efficacy specifically for fractionated electrograms (EGMs) encountered during atrial fibrillation (AF) catheter ablation (CA).
• To assess the impact of electrogram length on the accuracy of CL estimation for each method.

Main Methods:

• Three LAW detection algorithms were evaluated: hyperbolic tangent (HT) function, adaptive amplitude threshold (AAT), and CL iteration (ACLI).
• Performance was assessed against expert manual annotations using confusion matrices and CL error calculations across different EGM fractionation types.
• The influence of EGM recording length on individual CL error was analyzed for each detection method.

Main Results:

• The HT method demonstrated high accuracy (92.77-100%), sensitivity, and precision, outperforming AAT and ACLI (78.89-99.91%).
• The HT method exhibited lower CL error (up to 12 ms) compared to AAT and ACLI (up to 20 ms), particularly in complex EGMs.
• The HT method showed minimal dependency on EGM length, yielding the lowest and most consistent error values.

Conclusions:

• The hyperbolic tangent (HT) method significantly enhances atrial cycle length (CL) estimation accuracy and robustness compared to existing local activation wave (LAW) detection techniques.
• The HT method's high precision and reliability, especially with fractionated electrograms, make it suitable for integration into catheter ablation (CA) mapping devices.
• Implementing the HT method can potentially improve the success rate of ablation targets and overall outcomes in catheter ablation procedures for atrial fibrillation (AF).