Recurrent pseudo focal atrial tachycardia after ablation of persistent atrial fibrillation.

A 58-year-old male with recurrent atrial tachycardia (AT) after atrial fibrillation ablation was admitted for a second procedure. During the second procedure, the activation map showed a focal tachycardia with centrifugal activation. However, it was finally identified as a macroreentrant AT.This case highlights the significance of entrainment mapping in differentiating the mechanism of recurrent AT even when the activation map suggests focal AT. Focal AT can be excluded when a perfect post-pacing interval (PPI) is observed in the atrial segment opposite to the"earliest" activation site.