Case of atrial tachycardia originating from giant coronary sinus connected to persistent left superior vena cava: successful catheter ablation guided by noncontact mapping.

Radiofrequency (RF) catheter ablation is widely applied to tachyarrhythmia associated not only with structurally normal hearts but also with relatively mild cardiac anomalies. We present a case of 35 year-old female complaining of exercise-induced frequent palpitations caused by atrial tachycardia (AT) originating from giant coronary sinus (CS) connected to persistent left superior vena cava. AT was sensitive to intravenous ATP administration. Electrophysiological study partly using noncontact balloon of EnSite system clarified that two foci of AT were located at the orifice and the distal inner lumen of giant CS. After repetitive applications of RF energy to these origins, AT was not induced by drip infusion of isoproterenol. AT was not evoked by exercise without antiarrhythmic drugs 15 months after the RF ablation. This case indicates that RF ablation guided by noncontact mapping technique should be considered as a therapeutic regimen for AT associated with mild cardiac malformations.