Segmental pulmonary vein isolation in atrial fibrillation: new insights from the high density mesh mapper technique in an electrophysiologically guided approach.

Objective: As opposed to fundamental investigations into the nature of atrial fibrillation (AF) current clinical studies of AF ablation techniques sometimes only contain sparse information about the underlying electrophysiological properties. The purpose of this prospective, pilot study was to evaluate acute therapeutic success and clinical outcome after 6 month of segmental ostial ablation (SOA) using the High Density Mesh Mapper catheter (HDMM, BARD Electrophysiology, Lowell, MA, USA) for an electrophysiological guided approach. The HDMM is a novel, single expandable basket electrode catheter for high resolution recordings at the left atrium/pulmonary vein (PV) junction.

Methods: SOA was performed by irrigated radiofrequency (RF) application around the HDMM. Entry- and exit conduction block, as well as decreased local electrode amplitude, were endpoints for short-term successful ablation.

Results: Seventy-two patients with highly symptomatic paroxysmal AF (PAF; 47, 65.2%), persistent AF (12, 16.7%) and permanent AF (13, 18.1%) were studied. Entrance conduction block was obtained in 93%, exit conduction block in 81% of all PV. After 6 month no PV stenosis was observed, 62 patients (86.1%) improved clinically, whereas 52 patients (72.2%) were free from arrhythmias and sinus rhythm was present favoring patients with PAF.

Conclusions: In this first prospective study of PV isolation using the HDMM, our findings suggest, that this method is safe and yields good primary success rates and favourable clinical outcome at 6 month. The new technology based on high resolution recordings, offers beside good anatomical orientation a direct electrophysiological control for monitoring of bidirectional conduction block.