Persistent Atrial Tachycardia Mimicking Inappropriate Sinus Tachycardia: A Case Report

We report on a 57-year-old man with atrial tachycardia mimicking inappropriate sinus tachycardia that was sustained for 4 months despite pharmacotherapy. Using a noncontact mapping system (EnSite Array), the atrial earliest activation (EA) site was identified during tachycardia. By infusing the β1 antagonist landiolol and the β1 agonist isoproterenol, we varied his heart rate from 110 to 155 beats per minute. As his heart rate increased, the EA site moved from the top of the right atrial septum near the crist a terminalis to the right atrial append age (RAA). Tachycardia was terminated by multiple applications of radiofrequency catheter ablation to the RAA. Because the EA site of the sinus rhythm was distant from the ablation points, the tachycardia was diagnosed as persistent atrial tachycardia with multiple foci in a broad area around the RAA. On 12-lead electrocardiogram, the P-wave morphology in leads V1 and V2 changed from negative to positive upon termination of tachycardia