Impact of Radiofrequency Characteristics on Acute Pulmonary Vein Reconnection and Clinical Outcome After PVAC Ablation

Impact of Radiofrequency Characteristics. Objective: The objective was to study the impact of radiofrequency (RF) characteristics on acute pulmonary vein reconnection (PVR) and outcome after PVAC ablation. PVI with additional ablation of PVR (PVI+PVR) was compared to PVI-only. Methods: In 40 consecutive patients, after PVAC-guided PVI, adenosine and a 1-hour waiting time were used to unmask and ablate acute PVR (PVI+PVR group). RF-characteristics and 1-year AF freedom were compared post hoc to 40 clinically matched patients undergoing PVI only (PVI-only group). Custom-made software was used to assess RF characteristics of the PVAC applications needed to obtain baseline PVI. Results: There was no difference in clinical characteristics or baseline RF-profile between both groups. Acute PVR was observed and ablated in 38 of 160 veins (24%). AF-freedom after PVI+PVR was higher than PVI (85% vs 65%, P < 0.05). Within the PVI group, comparing patients with and without AF-recurrence, the percentage of PVAC applications with high T degrees (>48 degrees) but low power (< 3W) was higher (28 +/- 18% vs 11 +/- 11%, P < 0.0001). Within the PVI+PVR group, when comparing PVs with and without PVR, the percentage of low power/high T. PVAC applications was also higher (27 +/- 13% vs 13 +/- 15%, P < 0.0001). Conclusions: (1) After PVAC ablation, 24% of PVs exhibit acute reconnection. Additional ablation of reconnection improves clinical outcome. (2) Acute reconnection as well as clinical recurrence of AF are characterized by PVAC ablation with a considerable number of applications with high temperature but low power. (3) If PV isolation is obtained with low power applications, a consistent use of both adenosine and waiting time is required. (J Cardiovasc Electrophysiol, Vol. 24, pp. 290-296, March 2013)