Atrial Late Activation Mapping Predicts the Critical Isthmus of Left Atrial Re-entrant Tachycardia.

Functional atrial mapping is an emerging mapping modality to predict potential critical sites with a role in the maintenance of tachycardia. We report a case of atrial late activation mapping under sinus rhythm predicting the critical isthmus of a left atrial tachycardia. Our findings demonstrate the utility of an atrial isochronal late-activation mapping approach to predict the critical isthmus of re-entry.