The challenging face of focal atrial tachycardia in the post AF ablation era.

Radiofrequency ablation (RFA) for atrial fibrillation (AF) has become one of the most common catheter ablation procedures performed worldwide. As experience and success in treating patients with paroxysmal AF have increased, more centers are performing ablation for persistent AF. Optimal results may require ablation beyond the pulmonary veins with extensive biatrial substrate modification required in some cases to restore sinus rhythm. On the road to sinus rhythm atrial tachycardias are generally encountered either acutely within the index procedure or following. This has led to an increase in the frequency of focal atrial tachycardia and a need to review our understanding and approach to this and how it differs following substrate modification in contrast with the de novo setting. This review aims to describe the differences in responsible mechanism and its translation to mapping and ablation of focal AT particularly in the post ablation atria (paAT).