Co-Author(s):
Rokas Bendikas, MEng
Irum Kotadia, MBBS - King’s College London
Iain Sim, MBBS - King’s College London
Louisa O’Neill, MB, BCh, BAO - King’s College London
Caroline Roney, PhD - King’s College London
John Whittaker, MBBCh MA PhD - King’s College London
Steven Niederer, PhD - King’s College London
Mark O’Neill, MBBCh BAO DPhil - King’s College London
Steven Williams, BSc MBChB PhD
King’s College London
Westminster Bridge Rd, Bishop’s, London SE1 7EH
Introduction | Objectives: Slowing of atrial conduction velocity (CV) shortens the cardiac excitation wavelength and enables a greater number of wave fronts to be sustained within the atria, thereby perpetuating atrial fibrillation (AF). A reduction in atrial CV is a common finding among patients with AF when compared to controls. The objective of this study was to determine if differences in conduction velocity can be measured between patients with paroxysmal (PAF) and persistent atrial fibrillation (PsAF).
Methods: A retrospective analysis was performed in 180 patients with atrial fibrillation (90 PAF, 90 PsAF) presenting for index PVI between December 2015 and June 2018. Patients were included if a high-density CARTO map was collected from the left atrium during CS pacing prior to ablation lesions. Conduction velocity was calculated offline using openCARP, an open-source cardiac electrophysiology simulator. For regional analysis, the left atrium was segmented into five areas: Roof, anterior, septal, posterior and lateral. One-year recurrence rates were assessed in 149 of 180 patients (83%).
Results: The average age of patients was similar in both groups (61.1 vs 61.0 yrs, p= 0.98). Left atrial surface area was significantly larger in the PsAF group (197.4 vs 212.7 cm2, p = 0.002). Overall average CV was similar in the PAF and PsAF groups (0.68 ± 0.16 vs 0.69 ± 0.09 mm/ms, p = 0.70) (Fig 1). Increasing atrial size did not significantly correlate to CV slowing (p=0.16). There was no variation in regional CV in 4 of the 5 left atrial regions. (Anterior, Septal, Lateral and Posterior). There was, however, a significant increase in the conduction velocity in the Roof segment of the PsAF group (p = 0.04) (Fig 2). There was no difference in overall or regional CV between patients who had a recurrence of atrial arrhythmia within one year, versus the group who remained in sinus rhythm.
Conclusions: This study demonstrates that overall CV is similar in patients with PAF when compared to PsAF at the time of index PVI. The recurrence of atrial arrhythmias within the first year was not significantly correlated to CV.