Acute and long-term results of PVI at antrum using a novel high-density mapping catheter without help of 3D electro-anatomic mapping in patients with paroxysmal and chronic atrial fibrillation

Abstract

Multi-electrode circumferential mapping catheters have been developed by several manufacturers to facilitate catheter ablation procedures for atrial fibrillation (AF). We tested the effectiveness and safety of a conventional, fully endocardial electrogram-guided circumferential antrum isolation (PVI) with a novel mapping device. The study enrolled 250 consecutive patients with paroxysmal or chronic AF. High-density (HD) mapping of the pulmonary veins was performed with the HD Mesh Mapper (HDMM; Bard Electrophysiology, Lowell, MA, USA). The device was not constructed for radiofrequency energy delivery. Antral PVI was performed by irrigated radiofrequency application around the HDMM. Entry and exit conduction block, as well as decreased local electrode amplitude, were endpoints for acute successful ablation. Primary endpoint of the study was the AF free event probability during follow-up. As secondary endpoints, the acute results and related complications were determined. In 984 of 1,002 pulmonary vein (PV, 98.2%), signals were characterized as PV potentials by mapping the proximal part of the PV and the antrum. We achieved a complete antrum ablation in front of the 25-mm ring of the MESH Mapper in 95% of the PV in all patients. In difficult anatomic relationships, the repositioning of the mapping catheter could be necessary. The median follow-up time was 20.8 and 15.6 months in patients with paroxysmal and chronic AF, respectively. Log Rang test revealed a probability to be free from AF episodes of 71.2% and 49.4% after one ablation procedure and improved in chronic AF after a second procedure (71.1%). Our study demonstrates satisfactory success rate regarding the safety and long-term results in patients both with paroxysmal and persistent AF when a 3D mapping system is not being implemented. The study underlines the importance of a continuous signal analysis during the ablation procedure even with a conventional mapping system.