Follow-up
Each enrolled patient was followed up at 3, 6 and then every 6 months
subsequently by trained staff, either through a telephone interview or
at an outpatient clinic. During each follow-up, information related to
clinical results and medical treatment was collected. In addition,
24-hour Holter monitoring was performed, and 12-lead electrocardiograms
were recorded at every visit. Additional electrocardiograms were
performed if arrhythmic symptoms occurred. No atrial tachyarrhythmia
lasting at least 30 seconds beyond the 3-month blanking period was
defined as successful ablation.