Creating continuous linear lesions in the atria: A comparison of the multipolar ablation technique versus the conventional drag-and-burn

Introduction: Catheter-based treatment of atrial fibrillation (AF) requires the isolation of the triggering foci as well as modification of the atria with substrate that sustains AF. The creation of linear lesions in the left atrium with standard radiofrequency ablative methods requires long procedural times with unpredictable results. Methods: The simultaneous delivery of phase-shifted radiofrequency energy from a multipolar catheter was compared to the conventional drag-and-burn technique for creating linear lesions in 10 dogs. Four atrial sites were targeted under intracardiac ultrasound and fluoroscopic guidance in each of 10 dogs. The conventional drag-and-burn technique or the multipolar phase-shifted ablation catheter was randomly applied for 60 seconds and compared. Results: Creating linear lesions using the simultaneous multipolar phase-shifted ablation catheter was on average 11.0 minutes faster (33.6 minutes vs 44.6 minutes, P < 0.01) than the drag-and-burn method. The fraction of the lesion length achieved using phase-shifted ablation compared to that intended was 23% greater (76% vs 53%, P < 0.01), and has less discontinuities (0.1 compared to 0.8 discontinuities/line, P < 0.003). There was no significant difference in either the lesion transmurality, or fluoroscopy times. Conclusion: The simultaneous delivery of phase-shifted, radiofrequency energy using a multipolar catheter is more effective and efficient in producing linear lesions than the traditional drag-and-burn technique. Using the multipolar ablative method to create linear lesions may be a useful technique in the treatment of patients with substrate-mediated atrial fibrillation.