Atrial fibrillation (AF) and heart failure (HF) are complex clinical entities that occur concomitantly in a sigrnificant population of patients,and their prevalence is rising in epidemic proportions.Traditionally,both rate and rhythm control strategies have been regarded as equivalent in the management of dysrhythmia in this AF-HF cohort with escalation of treatment largely guided by symptoms.Both disorders are involved in an elaborate pathophysiological interplay with shared cardiovascular risk factors that contribute to the development and sustenance of both AF and HF.Recent studies and continued development of evidence to support catheter ablation for AF has brought into question the traditional belief in equivalence between rate and rhythm control.Indeed,recent trials,in particular the CASTLE-AF (Catheter Ablation versus Standard Conventional Therapy in Patients with Left Ventricular Dysfunction and Atrial Fibrillation) study,suggest that catheter ablation for AF improves survival and rates of hospitalisation in patients with concomitant HF and AF,threatening a paradigm shift in the management of this patient cohort.The evident mortality benefit from clinical trials suggests that catheter ablation for AF should be considered as a therapeutic intervention in all suitable patients with the AF-HF syndrome as these patients may derive the greatest benefit from restoration of sinus rhythm.Further research is needed to refine the evidence base,especially to determine which subgroup of HF patients benefit most from catheter ablation and what is the optimal timing.