Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia. Its prevalence increases with age1 and it has an increased long-term risk of stroke, heart failure and all-cause mortality.2 The UK’s population is ageing and it has been calculated that over 0.9% of the entire NHS budget is already spent on managing AF and its consequences, principally that of stroke.3

Catheter ablation is the newest non-pharmacological treatment for AF. Although catheter ablation of the atrioventricular node and pacemaker implantation has been available since 1982,4 the restoration and maintenance of sinus rhythm by ablation within the left atrium has evolved rapidly following the observation that most paroxysms of AF are initiated by ectopic depolarisations arising in the muscular sleeves of the pulmonary veins.5 Initially, successful ablation depended upon patiently waiting for unpredictable ectopic beats to arise within those veins and then to navigate the ablation catheter to their source and apply radiofrequency energy there. The strategies and technologies used today to achieve complete pulmonary vein electrical disconnection from the left atrium bear little resemblance to the ectopy-targeted ablation first practised over a decade ago.6

Patients were initially selected for ablation if drug treatment had failed while the electrophysiology community sought to improve its understanding of AF and to define the outcomes and limitations of the techniques used to treat it.7 Many centres can now offer an 80–90% likelihood of elimination of true paroxysmal AF,8 9 albeit after more than one procedure, often with additive ablation targeting focal non-pulmonary venous triggers.10 11 The interest has recently shifted from the paroxysmal patients for whom drugs have failed to redefining the populations of patients who might benefit from catheter ablation of AF and who were previously considered either inappropriate or too high risk …