Ablation procedure
AF ablation strategy of our center has been described
previously.9-10 Briefly, all patients underwent
transesophageal echocardiography to exclude left atrial thrombosis. All
antiarrhythmic drugs except amiodarone were stopped for at least five
half-lives before the procedure. The procedures were guided by CARTO
system under conscious sedation. A continuous irrigated radiofrequency
ablation (Navi-Star Thermocool, or Thermocool-Smart-touch Biosenes
Webster, USA) was performed along each pulmonary vein antrum in order to
encircle the ipsilateral pulmonary veins (maximum power: 35 W, infusion
rate: 17 ml/min). Procedural end-points were electrical isolation of all
pulmonary veins in the patients with paroxysmal AF. In the patients with
persistent AF, left atrial roofline, mitral isthmus and cavotricuspid
isthmus were routinely targeted. Cardioversion was performed if sinus
rhythm was not achieved after circle and line ablation. Additional
ablation was applied, if needed, to achieve pulmonary veins isolation
and linear block in sinus rhythm.
In repeat procedure, pulmonary veins isolation was achieved again if
recovered pulmonary veins conduction gaps existed. Conduction recovery
across ablation line was also ablated to achieve line block in those who
received linear ablation. Entrainment mapping and 3D activation mapping
were applied to identify the mechanism of organized atrial tachycardia.
The earliest activation site was ablated for focal atrial tachycardia
and the critical isthmus was ablated for macro-reentry atrial
tachycardia, respectively. Additional ablation of superior vena cava,
complex fractionated atrial electrograms were performed as the
operator’s discretion. The endpoints of the repeat procedure included
pulmonary veins isolation, bidirectional linear block if targeted and
non-inducibility of atrial tachyarrhythmias by burst pacing at minimum
interval with1:1 atrial capture.