AP Target Symposium 3 (II-APT3)
Dealing with congenitally corrected transposition of the great arteries - Efforts to minimize late development of systemic ventricular dysfunction

[II-APT3-03] Electrical issue of corrected TGA

^○Jun Yoshimoto (Department of Cardiology, Shizuoka Children's Hospital, Shizuoka, Japan)

In congenitally corrected TGA (ccTGA), there are several electro-anatomical issues. No.1 is an anatomical issue . SA node lies in normal position, but AV node (AVN) is in abnormal position. The actual position and course of AVN and His bundle differs case by case, especially because of straddling and DORV. Also connective tissue lies superficially and fragile. This seems to be the reason of occurrence of congenital and postsurgical complete AV block. No.2 is electrical and mechanical dyssynchrony. Bundle branch block of systemic ventricle causes electrical and mechanical dyssynchrony and they can be the cause of heart failure. In the case of univentricular physiology, however, interventricular dyssynchrony can cause severe heart failure. No.3 is tachy arrythmia post double switch operation. Both Senning and Mustard operation can cause intra atrial reentry tachycardia(IART). Ablation of IART of ccTGA has difficult problem because of anatomical abnormality of AVN, therefore brockenbrough puncture of intraatrial septum or baffle. Ablation of AVnodal Reentry tachycardia is quite difficult because of anatomical abnormality.