Ablation of Right Atrial Appendage Tachycardia Using 3D Electroanatomic Mapping System: A Rare Case Report

Atrial tachycardias (AT) originating from right atrial appendage (RAA) are quite rare among focal atrial tachycardias. A 38-year-old female patient presented to the emergency room complaining of palpitations and dizziness. Electrocardiography (ECG) showed regular narrow QRS complex tachycardia with a ventricular rate of 150 bpm. The patient had frequent episodes of palpitations for 5 years. Considering the ensuing tachycardiomyopathy under medical treatment, electrophysiological study (EPS) and ablation procedure was planned after having informed consent. During isoproterenol infusion (1-4 mcg/min), a sustained tachycardia with narrow QRS complex was induced. Diagnostic electrophysiological findings were consistent with AT. During tachycardia, by using a three-dimensional (3D) electroanatomic mapping system, simultaneous anatomical and activation mapping was performed with a quadripolar 3.5mm cooled-tip Thermocool Smarttouch bi-directional navigation catheter. Activation mapping demonstrated that the earliest endocardial activation site was basal portion of the RAA where the local electrogram was 104 msn prior to the Cs reference signal during tachycardia which is spreading in a centrifugal fashion. Impedance-controlled radiofrequency ablation (RF) ablation (35 W, 42° C, 5-10 g of contact force) was performed at the earliest site and tachycardia terminated in 10 seconds. No AT observed during the waiting period of 30 min after RF ablation.