Intracardiac Electrogram at Successful Site of Radiofrequency Catheter Ablation in Patients with Atrioventricular Nodal Reentrant Tachycardia

Bae, Jang Ho; Kim, Yoon Nyun; Kim, Kee Sik; Kim, Kwon Bae; Park, Jae Ho; Lee, Sang Min

Abstract

BACKGROUND AND OBJECTIVES
Ablation of the slow pathway in patients with atrioventricular nodal reentrant tachycardia (AVNRT) can be performed by using a specific intracardiac electrogram findings predicting a successful radiofrequency catheter ablation. The purpose of the present study is to recognize a specific intracardiac electrogram findings predicting a successful sites of radiofrequency catheter ablation in patients with AVNRT.
MATERIALS AND METHODS
The study population consisted of the 18 patients (7 males, mean age:46 yr) to undergo successful catheter ablation using radiofrequency current in order to eliminate AVNRT from January 1993 to september 1994. We have analyzed local intracardiac electrogram at successful and unsuccessful sites of radiofrequency catheter ablation before the radiofrequency application: Atrial electrogram amplitude, duration, number of peaks in atrial electrogram, atrial/ventricular (A/V) electrogram amplitude ratio, and presence of His potential and/or slow potential.
RESULTS
Of 18 patients, 16 patients underwent a slow pathway ablation, the other 2 patients a fast pathway ablation. The mean A/V electrogram amplitude ratio at successful and unsuccessful sites was 0.69+/-0.91 and 1.86+/-2.03, respectively. The mean atrial electrogram duration and number of peaks at successful and unsuccessful sites was 57+/-16 msec vs 69+/-16 msec and 1.7+/-0.5 vs 2.2+/-0.7, respectively. His bundle electrogram was seen in one slow pathway ablated and one fast pathway ablated patient. No slow potential could be identified in any of these 18 patients.
CONCLUSION
We think that A/V electrocardiogram amplitude ratio below 0.5 at posterior interatrial septum along tricuspid annulus is important marker indicating a successful ablation sites.