Use of a High Density Mapping System to Complete Wide Area Circumferential Ablation of the Pulmonary Veins and Avoid Ostial Segmental Ablation

Procedure involving catheter ablation to produce pulmonary vein isolation. Pulmonary veins are isolated by assessing electrograms circumferentially around the PV using the Orion catheter.

Catheters transiently inserted into body via femoral veins in order to produce pulmonary vein isolation. These catheters are the same in each arm and comprise the Orion catheter (Boston Scientific) and the Tacticath (St Jude) which are used to produce pulmonary vein isolation and which are approved for use in standard EP procedures by the relevant authorities (CE marked). It is merely the protocol by which they are used that iffers in the two arms.

Procedure involving catheter ablation to produce pulmonary vein isolation. Pulmonary veins are isolated by use of electroanatomical mapping with the Orion catheter around the sites ablation in order to target points of breakthrough.

Mapping activation patterns using the Rhythmia system in conjunction with the Orion catheter