SLL-Type CCTGA With Dual AV Conduction System: Anterior AV Node-Origin Atrial Tachycardia From RVOT
Xuesong Shi1,2, Mingyu Sun1, Zulu Wang1
1State Key Laboratory of Frigid Zone Cardiovascular Disease, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China.
Background:
Congenitally corrected transposition of the great arteries (ccTGA) involves atrio-ventricular/ventriculo-arterial discordance, leading to AV node-His bundle variations that complicate RVOT anterior AV node-origin atrial tachycardia (AT).
Case Summary:
A 16-year-old male with 3-year paroxysmal palpitations (worsened 6 months) had narrow QRS tachycardia. Echocardiography/CTA confirmed SLL-type ccTGA. Electrophysiologic study revealed dual AV conduction system (RVOT His potentials) and RVOT as the earliest activation site. Radiofrequency ablation succeeded, with no recurrence/AV block at 12-month follow-up.
Conclusion:
In ccTGA, pulmonary artery/RVOT is adjacent to the anteroseptum (aortic sinuses distant); redefining localization/ablation strategies ensures safety and success.
Related Concept Videos
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Dysrhythmias IV: Characteristics of Bradyarrhythmias
Conduction System of the Heart
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...
Conduction System of the Heart
This system relies on the unique properties of nodal and Purkinje cells:...
Dysrhythmias III: Characteristics of Dysrhythmias
Dysrhythmias II: Classification of Tachyarrhythmias


