Abstract
Background: It has been shown that post pacing interval (PPI) following increase in the entrainment pacing rate is stable in some macroreentrant atrial tachycardia (AT) and gradually increase in other macroreentrant AT. The purpose of this study is to evaluate the association between entrainment response and electroanatomical characteristics of AT. Methods: The PPI after entrainment at a rate 5, 10, 15 and 20 beats/minute faster than tachycardia rate were analyzed in 17 patients with stable macroreentrant AT. The increment of the PPI following increase in the pacing rate from 5 to 10 beats/minute (δPPI-10), from 5 to 15 beats/minute (δPPI-15) and from 5 to 20 beats/minute (δPPI-20) were compared between the PPI increment and stable patients. Results: The δPPI-10, δPPI-15 and δPPI-20 in PPI increment AT group were significantly longer than those in PPI stable group (16±5 vs. 2±3 msec; p<0.0001, 31±13 vs. 3±3 msec; p<0.0001 and 45±20 vs. 3±3 msec; p<0.0001, respectively). Focal radiofrequency energy application to the channel terminated the tachycardia in PPI increment ATs, whereas, a linear lesion to the isthmus was required in PPI stable ATs. Conclusions: Analysis of the PPI after entrainment is useful in differentiating the electroanatomical characteristics of reentry circuit of macroreentrant AT.
