Treatment of Atrial Fibrillation by the Ablation of Localized Sources: CONFIRM Trial

American College of Cardiology Foundation: January 14, 2013

Atrial fibrillation (AF) is the most common sustained arrhythmia¹ and catheter ablation aiming to eliminate tissue critical to AF² is found to be more effective than medications for its treatment.^3-5 Nevertheless, many patients require multiple, lengthy, and costly ablation procedures that confer at least modest risk.² AF ablation success is likely limited by the current available tools and lack of identification of AF sustenance mechanisms. There are currently two main competing hypotheses on mechanisms of AF sustenance:⁶ The multiple-wavelet hypothesis proposes that AF perpetuation is maintained by continuous annihilation and regeneration of randomly meandering electrical waves.⁷ Alternatively, the localized source hypothesis proposes that organized and fast reentrant circuits (rotors)⁸ or focal impulses⁹ are discrete and disorganize into fibrillatory waves at their periphery. However, until to date there has been only an indirect^10,11or no⁷ evidence to support localized sources in human AF. Narayan et al¹² presents a study testing the hypothesis that human AF, even with a wide range of presentations, is sustained by localized sources whose targeted ablation improves outcomes.