Far-Field Intracardiac Electrograms Removal Enables Highly Reliable Automatic Cycle Length Estimation During Atrial Arrhythmia

Electrograms (EGMs) from the intracardiac reference catheter placed in the coronary sinus (CS) vein are suscep-tible to ventricular noise. Most atrial tachycardia (AT) or fibrillation (AF) catheter ablation procedures use this lo-cation. Because of its proximity to ventricles, electrograms tend to include waves similar to the QRS complex (far-field activity) as seen on the electrocardiogram (ECG). These ventricular activities can, for instance, disturb the atrial cycle length estimation from those electrograms, or could fail its estimation. This study aims to determine whether the electrograms with ventricular far field (VFF) removed allow for higher cycle length estimation performance and reliable real-time diagnostic assistance. A method proposed in this paper separates and adaptively removes VFF while preserving useful atrial activity even when the two activities are su-perposed. This is achieved through generating a VFF blueprint from the time-frequency analysis using wavelet decomposition. Suppressing this blueprint in the wavelet domain and reconstructing the signal permits us to achieve artifact-free EGMs.