Electrophysiological study and ablation
All patients underwent ectopic ablation procedures under conscious
sedation, with cessation of all anti-arrhythmic drugs at least five
half-lives prior to the procedure. In each case a decapolar catheter was
placed in the coronary sinus and 3D electroanatomical mapping was
performed using a saline irrigated ablation catheter and one of two
mapping systems: CARTO (Biosense Webster Inc., CA, USA) or
NavX/Precision (Abbott Labs, IL, USA). Activation mapping was
predominantly used to determine the SOO, with supplementary information
provided by pace-mapping. Ablation was performed using a force sensing
catheter with RF energy at 25-35W with a 17 ml/min flow rate. 30-60
second lesions were created with a target impedance drop of 10 Ohms and
a temperature cut-off of 43 degrees Celsius.