Shift in the retrograde atrial activation sequence after radiofrequency catheter ablation in left variant atypical atrioventricular nodal reentrant tachycardia

The role of left AV nodal (SVN) connections in the genesis of "left-variant" atypical atrioventricular nodal reentrant tachycardia (AVNRT) and those with multiple retrograde pathways remain unclear. We describe an unusual case of "left-variant" atypical AVNRT, where change in the retrograde earliest atrial activation site (REAAS) at the coronary sinus (CS) following radiofrequency catheter ablation (RFCA) was observed. Our observation suggests that the REAAS, that is, the left AVN connections, could participate in the formation of the reentrant circuit of "left-variant" atypical AVNRT. Furthermore, its atrial breakthroughs involved as a circuit of SVT could be (functionally) multiple. (C) 2018 Elsevier Inc. All rights reserved.