Investigating the Optimal Recording Duration for Summarising Spatiotemporal Behaviours of Long Lifespan Rotors Using Phase Mapping of Non-Contact Electrograms During Persistent Atrial Fibrillation

Understanding the spatiotemporal behaviour of ‘rotors’ in human atrial fibrillation (AF) is important for using them as targets for ablation. This study aims to track the spatiotemporal stability of rotors over 5 min time interval during persistent atrial fibrillation (PersAF). This study involved 10 PersAF patients, who underwent catheter ablation. 2048 non-contact virtual unipolar electrograms (VEGMs) were simultaneously collected and resampled at 512Hz, QRST interval removed and reconstructed using a sinusoidal wavelet fitting approach (Kuklik et al. Subsequent density maps of rotors were generated. The VEGM were divided into a total of 60 segments of different durations starting from 5s, 10s, 15s and so on. The segments were further divided into; group A ≤ 30 s, group B > 30, density maps of different time durations were compared with the full 300 s. Rotor density maps in segments recorded in group A differed significantly from group B, (CORR: group A 10 s = 0.47 ± 0.064 Vs. 30 s = 0.69 ± 0.067 Vs. group B 45 s = 0.76 ± 0.066 Vs. 60 s = 0.80 ± 0.063; P<0.0001). Rotor density maps for group B showed higher similarity and lower variation (0.88 ± 0.092) when compared to group A (0.53 ± 0.134). Our results suggest that time duration ≤ 30 s is not sufficient to detect/track spatiotemporal organization of rotors in PersAF patients.