4. Percutaneous catheter radiofrequency ablation
A three-dimensional endocardial electroanatomical mapping system (Johnson & Johnson, USA) was used to create and verify radio frequency injuries for all patients. Computed tomography can help to optimize the three-dimensional reconstruction. The ablation catheter and the circular catheter (BiosenseWebster, USA) used for recording and stimulation were both percutaneously punctured into the femoral vein and entered left atrium through the atrial septal. The radiofrequency signal was transmitted through an irrigation needle catheter (3.5 mm) equipped with a thermocouple. The target temperature was 45°C, and the power was 40W, which caused localized damage to the myocardium with a diameter and depth of 3 to 4 mm. As mentioned above, the radiofrequency injury was around the ipsilateral pulmonary vein, and the purpose was to establish a bidirectional conduction block between the left atrium and pulmonary vein, and reduce the local myocardial voltage to <0.15 mV, which could eliminate the pulmonary vein potential.