Radiofrequency ablation procedure
All procedures were performed according to standard of care and current
guidelines. Patients were under efficient stable oral anticoagulation
for at least four weeks with no interruption prior to ablation. Contrast
cardiac computed tomography or transesophageal echocardiography was
performed the day before the procedure to rule out intracardiac
thrombus. All patients underwent ablation under mild or deep assisted
sedation or general anaesthesia. After venous femoral access,
intravenous heparin was infused targeting an activated clotting time
(ACT) >300 s. ACT was tested every 30 min, and additional
heparin was applied if necessary. Trans-septal puncture was performed by
standard technique under fluoroscopy and transoesophageal
echocardiography guidance when needed. Electroanatomic mapping was
completed using IntellaMap Orion™. Radiofrequency (RF) ablation was
performed with standard 4-mm-tip irrigated catheter (Celsius
Thermocool™, Biosense Webster; Blazer OI™, Boston Scientific), magnetic
irrigated catheters (IntellaNav OI™, Boston Scientific) or with contact
force sensing irrigated catheters (Tacticath™, St. Jude Medical). PVI
was achieved using a wide circular antral linear lesion. Additional
lesion sets including linear lesions and ablation of complex
fractionated atrial electrograms for persistent AF procedures were
performed at the physician’s discretion. For AT, ablation targeted the
critical isthmus or the area of focal origin.Pulmonary veins entrance
and exit blocks, as well as bidirectional blocks for linear lesions were
confirmed by conventional pacing and/or activation mapping. After
procedure completion, the patient was monitored in the recovery unit
then discharged 24 to 48 hours later after clinical examination, ECG and
transthoracic echocardiography. .