Introduction
Dual atrioventricular (AV) nodal physiology is a common finding during
an electrophysiologic study. This finding provides a substrate for the
common form of atrioventricular nodal reentrant tachycardia
(AVNRT)1. The typical form of AVNRT (slow-fast type)
shows a short R-P or a simultaneous R-P during tachycardia with heart
rates usually ranging from 150/min to 220/min2. Pseudo
R’ in V1 is a common feature. However, if the heart rate during
tachycardia is relatively slow, junctional tachycardia (JT) emerges as
part of the differential diagnosis. Notably, while catheter ablation of
AVNRT has been reported with a very high success rate and low incidence
of heart block2, catheter ablation of JT has a lower
success rate and higher rates of complete heart block. Therefore, during
the electrophysiological study, using maneuvers such as atrial overdrive
pacing (AOD) and atrial extrastimulus (AES)3,4 to
differentiate AVNRT and JT is important.
In this study, we reported a series of patients with slow, symptomatic
typical AVNRT below 110 bpm resembling JT, which were successfully
diagnosed and ablated.