Omnipolar activation EGM to identify the earliest breakout site of atrial tachycardia.

AT was mapped with Advisor HD Grid for earliest breakout site via local activation timing (LAT) map and Omnipolar map. While both maps point to earliest breakout site from low anterior right atrium, omnipolar map localised it to a more precise location compared to the earliest breakout site from LAT map. Ablation in this same spot rendered AT non inducible.