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.