Coalescence of splines on a basket mapping catheter during ablation using a closed-loop irrigation catheter

Abstract

We performed pulmonary vein isolation (PVI) for treatment of symptomatic drug-refractory atrial fibrillation (AF) in a 52-year-old man by using the Constellation® basket mapping catheter (Electrophysiology Technologies, Boston Scientific, Natick, MA, USA), which consists of 64 bipoles on 8 splines. The catheter was placed in the ostium of each pulmonary vein (PV). A 4 mm Chilli II™ internal irrigation radiofrequency (RF) catheter (Boston Scientific) was used to deliver RF energy to each PV. The irrigation rate was 36 mL/min. The target bipole was the earliest activation point of the PV ostium adjacent to the splines, with the splines placed on the atrial side of the PV antrum. Location of the catheter tip relative to the mapping catheter was confirmed by using the EnSite NavX™ three-dimensional mapping system (St Jude Medical, St Paul, MN, USA) to determine the position of the ablation catheter relative to the bipole. Furthermore, a ‘bumping’ artefact, resulting from manipulation of the ablation catheter, could be visualized on the mapping catheter. We applied RF energy at a maximum power of 32–35 W and a maximum temperature of 39–40°C. To confirm the ablation catheter's position, we assessed for the presence of ‘bumping’ artefacts …