Background
Radiofrequency (RF) ablation is a widely accepted and effective therapy in the management of atrial fibrillation (AF)1–3. However, ablation of persistent atrial fibrillation remains a therapeutic challenge, with recurrence rates of 30-60% at one year, and a frequent need for repeat ablation.4–7 Improved catheter stability results in more consistent catheter-tissue contact, both allowing for more effective transmural lesion formation and preventing excessive force that could result in cardiac perforation. Furthermore, improved catheter stability has been shown to be associated with decreased arrhythmia recurrence following AF ablation.8 Multiple strategies and techniques exist for improving catheter stability, including high frequency jet ventilation9–11, steerable catheter sheaths11–13, and rapid atrial pacing14. However, catheter stability may be affected by the underlying atrial rhythm. In patients with persistent AF, achieving stable sinus rhythm and reliable atrial pacing may be challenging prior to ablation, and pacing can only be performed in the ventricle. It is unknown whether ablation in AF with ventricular pacing versus in sinus rhythm (SR) with atrial pacing has any effects on catheter stability, lesion quality, or clinical outcomes. In the present study, we sought to compare the ablation characteristics and clinical outcomes between patients with persistent AF who were mapped and ablated in sinus rhythm with atrial pacing compared to atrial fibrillation with ventricular pacing.