Incessant non-reentrant supraventricular tachycardia interrupted by apparent simultaneous wenckebach sequences along both nodal pathways.

We report a new case of non-reentrant supraventricular tachycardia, associated with tachycardia-induced cardiomyopathy fully reversible after radiofrequency (RF) ablation, together with striking features of apparent concomitant Mobitz type 1 atrioventricular (AV) block in both AV node pathways. Further analysis of the conduction patterns during the incessant non-reentrant tachycardia raised unresolved hypothesis about the involved mechanisms and further interrogations on AV node physiology.