Initial experience with the high-density mesh ablation catheter for pulmonary vein isolation.

Background: Pulmonary vein isolation (PVI) is usually performed with multiple point-by-point radiofrequency ablation with a second multielectrode circular mapping catheter to validate isolation. We evaluated a 30-mm high-density mesh electrode (HDMA) for mapping and PVI in patients with recurrent atrial fibrillation (AF).

Methods: In 13 patients (validation group) up to three pulmonary veins (PVs) were targeted with the HDMA. A circular mapping catheter was used to validate PVI. PVI was completed with a CARTO-guided approach (Biosense Webster, Diamond Bar, CA, USA) followed by a voltage remap. In 11 patients (feasibility group) the HDMA catheter was evaluated as a stand-alone mapping and ablation tool.

Results: The diagnostic accuracy of the HDMA catheter to evaluate PVI was 100%. The encircled low-voltage area (<0.15 mV) after HDMA-guided PVI was smaller compared to CARTO-guided PVI. In the feasibility group 76% of the PVs could be isolated. Complete isolation of all PVs was feasible in five patients (45%) with a mean procedure and fluoroscopy time of respectively 180 +/- 39 minutes and 40 +/- 14 minutes. After 1 year 64% of the patients were free of symptomatic AF.

Conclusions: The HDMA electrode is a reliable mapping tool to validate PVI. The majority of PVs can be isolated, but on a patient basis touch-up ablations are necessary in more than 50% of the cases. Therefore, modifications in catheter design are required. The small area of voltage abatement points to an ostial left atrium-pulmonary vein disconnection. Initial clinical results in a small number of patients are promising.