Pulmonary vein isolation by duty-cycled bipolar and unipolar antrum ablation using a novel multielectrode ablation catheter system: first clinical results
The electrical disconnection of the pulmonary veins (PV) plays an important role in the ablation strategy of paroxysmal atrial fibrillation (PAF). Circumferential antral ablation with a conventional ablation technique using a steerable ablation catheter is sometimes difficult to perform and does not always result in isolation of the targeted PV. Patients with symptomatic PAF were treated with a novel circular mapping/ablation catheter (PVAC). Ablation was performed in the antral region of the PV with a power-modulated bipolar/unipolar RF generator using 8–10 W until isolation of the vein was achieved. Seven-day Holter monitor recordings were performed off antiarrhythmic drugs at 3 and 6 months after the initial procedure. A subgroup of patients had received an implantable recorder before ablation, and the device was interrogated at the same time. The primary objective of this study is acute isolation of the targeted PV, and the second objective is clinical efficacy with a short-term follow-up. In 73 patients, 290 PV could be reached with the PVAC. Antral ablation was performed in 244 PV showing PV potentials. Acutely, 243 PV (99%) were isolated with the PVAC after 21 ± 7 energy applications per patient with a mean fluoroscopy time of 20 ± 11 min. Total procedure time was 122 ± 27 min. No complications were observed. Follow-up at 3 and 6 months showed freedom from AF in 61 of 73 (84%) patients and 38 of 45 patients (85%), respectively, off antiarrhythmic drugs. PV isolation by duty-cycled unipolar/bipolar RF ablation can be effectively and safely performed with a circular, decapolar catheter. Clinical results at 3 and 6 months after ablation are encouraging with the need for longer follow-up intervals.