Contact force sensing technology identifies sites of inadequate contact and reduces acute pulmonary vein reconnection: a prospective case control study.

BACKGROUND: Contact force (CF) sensing technology allows real time CF measurement during catheter ablation. We hypothesised that the use of CF technology during pulmonary vein isolation (PVI) for atrial fibrillation (AF) would translate into lower acute pulmonary vein (PV) reconnection rates. METHODS AND RESULTS: Symptomatic AF patients were treated in two groups, 'unblinded' and 'blinded', each containing 20 patients undergoing first time PVI. An irrigated radiofrequency CF sensing catheter was used in both groups. In the 'unblinded' group, the operator could view the CF value during mapping and ablation in real time. In the 'blinded group', the operator was 'blinded' to this information during the procedure, although the data were recorded. All 80 PVs were successfully isolated with exit and entrance block re-tested after 1h with adenosine. There was a significant association between blinding and the rate of acute PV reconnection. 17/80 (21%) of the PVs in the blinded subjects had a reconnection while 3/80 (4%) of the PVs in the unblinded subjects had a reconnection (p=0.001). Blinding the operator resulted in lower mean CF overall (11.6g (10.5, 12.9 g) vs. 14.4 g (13.3, 15.7 g); p=0.002). Sites where applied CF was significantly lower than others were usually the sites where reconnection occurred: these were the ridge between the left upper PV and appendage, and the right carina. CONCLUSIONS: CF data identified key areas where CF was poor. These were the areas of acute reconnection. Availability of real time CF information during PVI was associated with a significantly lower acute pulmonary vein reconnection rate.