Termination of Atrioventricular Nodal Reentrant Tachycardia by Premature Stimulation From Ablating Catheter A Reliable Guide to Identify Site for Slow-Pathway Ablation

Background Slow-pathway ablation is currently used more frequently to control atrioventricular nodal reentrant tachycardia (AVNRT). However, in patients with the common type of AVNRT, successful ablation of the slow pathway can be difficult and time-consuming. We tested a simple method to predict a site for slow-pathway ablation in patients with AVNRT of the common variety. Methods and Results Twenty patients with symptomatic common AVNRT (13 women and 7 men; mean age, 41±21 years) were included in the study. Once the AVNRT had a stable cycle length (±10 ms) for at least 20 cycles, single extrastimuli were delivered from the ablating catheter tip beginning with 20 ms less than the tachycardia cycle length and decrementing by 10 ms until tachycardia terminated or loss of capture occurred at the pacing site. The pacing protocol was performed systematically in a stepwise fashion at four adjacent sites starting from the posterior/inferior interatrial septum near the tricuspid annulus and moving progressively ...