Paced P-wave morphology templates to guide atrial tachycardia localization: A derivation and validation study.

Background: Surface ECG is a useful tool to guide mapping of focal atrial tachycardia (AT).

Objectives: We aimed to construct 12-lead ECG templates for P-wave morphology (PWM) during endocardial pacing from different sites in both atria in patients with no apparent structural heart disease (derivation cohort), with the goal of creating a localization algorithm, which could subsequently be validated in a cohort of patients undergoing catheter ablation of focal AT (validation cohort).

Methods: We prospectively enrolled consecutive patients who underwent electrophysiology study, had no structural heart disease and no atrial enlargement.