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Published on: July 20, 2022
Short-Time Estimation of Fractionation in Atrial Fibrillation with Coarse-Grained Correlation Dimension for Mapping
Aikaterini Vraka1, Fernando Hornero2, Vicente Bertomeu-González3
1BioMIT.org, Electronic Engineering Department, Universitat Politecnica de Valencia, 46022 Valencia, Spain.
Insights
A new method accurately estimates electrogram fractionation during atrial fibrillation ablation. This technique aids catheter ablation procedures by reliably identifying complex fractionated atrial electrograms for improved patient outcomes.
Area of Science:
- Cardiology
- Biomedical Engineering
- Signal Processing
Background:
- Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia.
- Pulmonary vein catheter ablation (CA) is a primary treatment for AF.
- Identifying complex fractionated atrial electrograms (CFAEs) outside pulmonary veins improves long-term CA success.
Purpose of the Study:
- To develop and validate a real-time electrogram (EGM) fractionation estimator for assisting catheter ablation (CA) procedures.
- To improve the identification of complex fractionated atrial electrograms (CFAEs) for enhanced AF treatment.
Main Methods:
- Coarse-grained correlation dimension (CGCD) was computed on 1-second epochs of atrial electrograms.
- The method was tested on three groups of AF recordings (n=24, n=119, n=20 pseudo-real EGMs).
- 10-fold cross-validation and receiver operating characteristic (ROC) analysis were used to evaluate performance.
Main Results:
- Achieved 100% classification accuracy in a representative EGM group and 84.0-85.7% in a larger dataset.
- Demonstrated high specificity (87.5-100%) and sensitivity (93.6-100%) in identifying fractionated EGMs.
- Correctly identified 100% of pseudo-real Type IV AF electrograms.
Conclusions:
- The proposed CGCD method reliably quantifies EGM fractionation in atrial fibrillation.
- This technique offers improved performance over existing methods for real-time AF EGM analysis.
- The method can aid in mapping atrial substrates and guiding CA procedures for atrial substrate modification.
Abstract:
Atrial fibrillation (AF) is currently the most common cardiac arrhythmia, with catheter ablation (CA) of the pulmonary veins (PV) being its first line therapy. Ablation of complex fractionated atrial electrograms (CFAEs) outside the PVs has demonstrated improved long-term results, but their identification requires a reliable electrogram (EGM) fractionation estimator. This study proposes a technique aimed to assist CA procedures under real-time settings. The method has been tested on three groups of recordings: Group 1 consisted of 24 highly representative EGMs, eight of each belonging to a different AF Type. Group 2 contained the entire dataset of 119 EGMs, whereas Group 3 contained 20 pseudo-real EGMs of the special Type IV AF. Coarse-grained correlation dimension (CGCD) was computed at epochs of 1 s duration, obtaining a classification accuracy of 100% in Group 1 and 84.0-85.7% in Group 2, using 10-fold cross-validation. The receiver operating characteristics (ROC) analysis for highly fractionated EGMs, showed 100% specificity and sensitivity in Group 1 and 87.5% specificity and 93.6% sensitivity in Group 2. In addition, 100% of the pseudo-real EGMs were correctly identified as Type IV AF. This method can consistently express the fractionation level of AF EGMs and provides better performance than previous works. Its ability to compute fractionation in short-time can agilely detect sudden changes of AF Types and could be used for mapping the atrial substrate, thus assisting CA procedures under real-time settings for atrial substrate modification.
