[Paroxysmal and persistent atrial fibrillation: New therapy concepts for pulmonary vein isolation - First clinical experiences with the High Density Mesh Ablator (HDMA)].

Background and Objectives: Interventional therapy of atrial fibrillation (AF) is often associated with long examination- and fluoroscopy times. The use of mapping catheters in addition to the ablation catheter requires multiple transseptal sheets for left atrial access. The HDMA was introduced in 2007 for the the segmental and circumferentil ablation of paroxysmal atrial fibrillation. In small experimental study groups the new catheter system was validated for its electrophysiological properties. The purpose of this prospective study was to evaluate feasibility and safety of pulmonary vein (PV) isolation using the High Density Mesh Ablator (HDMA), a novel single, expandable electrode catheter for both mapping and radiofrequency (RF) delivery at the left atrium/PV junctions.
Patients and Methods: 40 patients with highly symptomatic paroxysmal AF (PAF, 23/57,5 %) and persistent AF (CAF, 17/42,5 %) were studied. PV isolation via the HDMA was performed using a customized pulsed RF energy delivery program (target temperature 55 - 60 degrees, power 70 - 100 Watt, 600 - 1000 seconds RF application time/PV).
Results: All 158 PV in 40 patients could be mapped and ablated by the HDMA. Segmental PV isolation was achieved with a mean of 3,75 +/- 1,9 RF applications for a mean of 715 +/- 375 sec. Entrance conduction block was obtained in 93,5 % of all PV. Mean total procedure and fluoroscopy time was 152 +/- 34 min and 29 +/- 10 min respectively. None of the patients experienced severe complications. After 3 month 78 % of the patients with PAF and 41 % with CAF respectively were free of AF.
Conclusions: In this first study of PV isolation using the HDMA, our findings suggest that this method is feasible, and yields good primary success rates. Due to single transseptal access the HDMA simplifies the complex procedure of AF ablation, favorably impacting procedure and fluoroscopy times.
(Georg Thieme Verlag KG Stuttgart * New York.)