Catheter ablation procedure
In the present study,patients underwent left atrial and pulmonary venous computed tomography angiography or transesophageal echocardiography prior to CA to rule out thrombosis. The strategy of CA for AF in our center has been described before21. In brief, after atrial septal puncture, a 3.5mm tip ablation catheter was used to reconstruct the left atrial geometry under the guidance of the CARTO system. In patients with paroxysmal AF, pulmonary vein isolation (PVI) was performed with the endpoint of electrical isolation. In addition, patients with recordings of typical atrial flutter underwent tricuspid isthmus ablation. In patients with persistent AF, linear ablation (mitral isthmus line, left atrial roof line and cavotricuspid isthmus line) was performed in addition to PVI, with the endpoint of bidirectional block across each of the 3 ablation lines as described previously. If the sinus rhythm (SR) was not reached after the ablation procedure, cardioversion was performed. For the repeated procedure, in brief, the pulmonary veins (PVs) were checked to assess the PV reconduction, and PVI was achieved by the gap ablation. Moreover, if necessary, additional ablation was performed (such as complex fractionated atrial electrograms, superior vena cava) at the discretion of the operator.
Continuous infusion of heparin during the ablation was used to maintain the activated clotting time (ACT) of 300-400 seconds. We monitored every 30 minutes throughout the ablation procedure to maintain the target ACT.