[Focal atrial tachycardia originating in the right atrial appendage].

We present a case of 14-year-old boy with incessant atrial tachycardia from right atrial appendage, resistant to pharmacotherapy and with early signs of the left ventricle tachyarrhythmic dysfunction. The P-wave was positive in leads I, II, III, aVF, negative in aVR, aVL. Moreover, P waves configuration specific for this localization: negative in V1-V2 that become positive in V3-V6 was present. After first ablation session a recurrence was observed after 3 weeks, due to inadequate power delivery resulting from trabeculation/anatomy that limited conventional ablation catheter cooling. Second ablation session with the use of an active electrode cooling and 3D mapping system was successful.