Ablation of Focal Activation in Atrial Fibrillation

Inclusion Criteria: * Persistent atrial fibrillation with clinical indication for catheter ablation * Clinically suitable candidate for catheter ablation * Signed informed consent Exclusion Criteria: * Previous atrial fibrillation or other catheter ablation procedure * Clinical contraindication to catheter ablation or general anaesthetic, including history of adverse reaction to contrast media, or presence of intracardiac thrombus, or inadequate anticoagulation in the preceding 6 weeks * Valvular disease graded moderate or greater, or presence of a prosthetic valve * Moderate-to-severe heart failure, defined as left ventricular ejection fraction \<35% and/or New York Heart Association class III-IV * Any form of cardiomyopathy * Active infection or fever * Severe cerebrovascular disease * Active gastrointestinal bleeding * Bleeding or clotting disorders, clinically high bleeding risk, or clinical contraindication to receiving heparin * Baseline serum creatinine \>200umol/L * Currently receiving or at risk of requiring renal replacement therapy * Uncontrolled diabetes (HbA1c ≥73mmol/mol or HbA1c ≤64mmol/mol and fasting blood glucose ≥9.2mmol/L) * Malignancy necessitating therapy * Life expectancy shorter than the duration of the trial * Pregnancy, or childbearing potential and not using a highly effective method of contraception * Inability to provide informed consent to participate in the trial