The quadripolar catheters used for the transesophageal electrophysiological study is an alternative in such cases due to limitations of vascular access and size of the pediatric patients, additional catheter for intracardiac electrograms cannot be placed in atria stable position.To aim of this article is to report the effectiveness of transesophageal electrode as a reference catheter in patients with limited vascular access and complex congenital heart disease during ablation procedures. Transesophageal catheters can be used as an alternative to the reference catheter in the electrophysiology laboratory for provoking or terminating arrhythmias, understanding mechanism of arrhythmias or as an aid in mapping