Ablation procedure
pericardial effusion, bleeding
PERICARDIAL EFFUSION, EVENTS, BLEEDING
Ablation procedures were performed under conscious sedation with continuous infusion of fentanyl. Under local anesthesia, after successful puncture of the bilateral femoral veins, a loading dose of 120 U/kg heparin was administered to achieve an activated clotting time (ACT) ≥ 300 S while ablation energy was delivered. A 6F diagnostic decapolar catheter (MicroPort EP, Shanghai, China) was positioned in the coronary sinus via the left femoral vein. After two 8.5F Swartz SL1 sheaths were advanced via the right femoral vein, sequential double transseptal punctures were performed under fluoroscopic guidance. The transseptal sheaths were continuously flushed with heparinized saline throughout the ablation procedure. A circular decapolar catheter (MicroPort EP, Shanghai, China) was inserted into the left atrium through a transseptal sheath to record the pulmonary vein ostia potential. A 3.5 mm open-irrigated ablation catheter (the STSF catheter for patients in the HPSD group, and the ST catheter for patients in the conventional group; Biosense-Webster, Diamond Bar, CA) was advanced through another transseptal sheath into the left atrium for ablation therapy. The three-dimensional electro-anatomic reconstruction of the left atrium (including atrium, pulmonary veins, left atrial appendage, mitral valve annulus) was performed using the irrigated ablation catheter under the guidance of the CARTO3 mapping system (CARTO 3 V6, Biosense-Webster, Diamond Bar, CA). Wide-area circumferential PVI was performed point-by-point under the guidance of the CARTO3 mapping system with an automated ablation lesion tagging program (VisiTag™ Module, Biosense-Webster, Diamond Bar, CA). The VisiTag criteria were set as follows: range of catheter motion ≤ 2.5 mm for 3S and contact force ≥ 5 g for more than 40% of the time. For patients in the HPSD group, RF energy was adjusted to 50 W, temperature 43 °C, contact force 5–20 g, and flow rate 20 mL/min using the novel STSF catheter, while for patients in the conventional group, RF energy was adjusted to 30–35 W, temperature 43 °C, contact force 5–20 g, and flow rate 17–30 mL/min using the ST catheter. For all enrolled patients, the target ablation index was set at 500 on the anterior wall and 350 on the posterior wall of the left atrium. Circumferential PVI was performed in all enrolled patients. Additional ablation lesions were performed at the discretion of the operator. If AF persisted after ablation, electrical cardioversion was performed to restore the sinus rhythm. With the mandatory administration of additional heparin, ACT was monitored every 30 min to maintain the target of 280–350 S throughout the ablation procedure. Anticoagulation therapy was resumed 4–6 h after the procedure when pericardial effusion and bleeding events were excluded by bedside echocardiography with ACT < 180 S.