Co-Author(s):
Chu Gavin, MBChB, PhD
Xin Li, PhD
Zakariyya Vali, MBChB, MRCP
Akash Mavilakandy, MBChB
Tiago Paggi De Almeida, PhD
Andre Ng, MBChB, MRCP, PhD - Professor in electrophysiology, University of Leicester
University of Leicester
University road, Leicester, UK
Introduction | Objectives: Clinical classification (paroxysmal vs. persistent) for atrial fibrillation (AF) remains inadequate for informing substrate underlying arrhythmogenesis and recurrence. This study was performed to examine P waves during sinus rhythm (SR) following DC cardioversion (DCCV)  using high-density body surface mapping (BSM) to correlate with DCCV outcome 12 months to provide insight on possible underlying substrate.
Methods: 56 patients who underwent DCCV for AF were recruited. P-wave duration corrected by heart rate (PWDc), P-wave amplitude (PWA) and P-wave temporal stability (TS) were measured using 128-lead BSM immediately following DCCV. A bandpass filter (1- 50 Hz) was applied to the signal and analysis performed using custom written MATLAB software. Patients were stratified based on amiodarone therapy. Patients were followed up to 12 months for AF recurrence.
Results: Four patients were excluded due to lack of follow up and spontaneous reversion to sinus rhythm (SR) just before DCCV. Of the 52 patients analysed, successful DCCV to SR occurred  in 98.1% and maintenance of SR at 12 months in 44.2%. In patients on amidarone (n=23), PWDc was shorter in those who maintained SR at 12 months vs. those who had remission to AF (83.13ms vs 112.2ms, P=0.043). ROC analysis exhibited a cut-off of >86.67ms for recurrence with AUC of 0.77, sensitivity of 78.57% and specificity of 77.78% (Figure 1).   PWA and TS were not significantly predictive of outcome at 12 months in patients who were not on amiodarone (n=29).
Conclusions: In patients who were on amiodarone at DCCV, increased PWDc measured by BSM immediately after DCCV was associated with AF relapse at 12 months.  This may be due to atrial remodelling or substrate related issues. A cut-off value of >86.67ms was predictive of AF recurrence
AFS 2021-44