Catheter Ablation of Atrial Tachycardia Originating From the Posterior Wall of the Left Atrium Following Prior Atrial Fibrillation Ablation: A Case Report

This case report describes a 56-year-old male with recurrent symptomatic atrial tachycardia (AT) following prior extensive atrial fibrillation ablation, including posterior wall isolation. Surface ECG suggested a possible pulmonary vein origin, but high-density 3D electroanatomic mapping precisely localized the focus to the left atrial posterior wall. Radiofrequency ablation at the earliest activation site terminated the tachycardia promptly. The patient remained symptom-free during a 3-month follow-up. This case highlights the importance of detailed mapping in localizing rare AT origins after prior ablation, the challenges of ECG interpretation in altered substrates, and the feasibility of safe and effective ablation in the posterior wall region with controlled energy delivery.