Follow up
Antiarrhythmic medications were continued for a minimum of 3 months post ablation and then weaned or ceased at the discretion of the treating physician. Follow-up included clinical assessment and 12 lead ECG, at 3, 6 and 12 months and then ongoing follow-up as dictated by symptoms. Patients with implantable cardiac devices capable of AF detection (dual chamber device or implantable loop recorders) had device interrogation performed at 3 months then yearly as a minimum. Patients without an intracardiac device underwent 48 hours of ambulatory monitoring at either 3 or 6 months follow-up with further monitoring dictated by symptoms. Recurrence was defined as documented AF/AT >30 seconds with or without clinical symptoms, or recurrence requiring pharmacological or interventional treatment, beyond a 3 month post procedural blanking period. The ongoing use of antiarrhythmic drug therapy was not counted as failure (since this was not part of a trial with a protocol to stop them necessarily) but the success rate is reported on and off antiarrhythmic drugs. Information was obtained from the hospital data-registry and verified by assessment of hospital medical records. Cardiac specific beta-blockers specifically used for heart failure therapy were not classified as anti-arrhythmic agents. Repeat ablation was offered to patients with symptomatic recurrence as clinically indicated and was performed exclusively with RF ablation. The ablation strategy involved PV re-isolation followed by mapping of induced or spontaneous atrial tachycardias and further substrate-based ablation at the operator discretion.