Cathrter Aboation of The Posteroseptal Accessory Pathways

Abstract

Background：The ablation of accessory pathways(APs using radiofrequency(RF energy has been established as a primary modality of treatment for atrioventricular reentrant tachycardia with proven safety and high rate of success. However, the ablation of posteroseptal(PS APs had been recognized as being more difficult to ablate than those in other location because of the complex three dimensional anatomy of the posterior space, and multifarious approaches have been proposed. We analyzed electrophysiologic characteristics and results of catheter ablation of 70 consecutive patients, who underwent RF ablation of PS APs with or without booster direct current(DC shock. Methods：The AP location was confirmed to be in the PS region, ablation was attepmted at the atrial aspect of the tricuspid annulus adjacent to the coronary sinus ostium, within the coronary sinus including middle cardiac vein, or underneath the mitral annulus close to the septum using retrograde transaortic approach if deemed necessory. A continuous, unmodulated sine wave radiofrequency generator was used as the source of energy for ablation. The site was considered optimal for ablation when the electrogram obtained from the ablation catheter had one or more of the following characteristics：(1 short VA intervals with an A：V ratio of ≤1.0 and discrete, high frequency potentials or fractionated electrograms between local atrial and ventricular deflections(accessory pathway potential；(2 ventricular activation occurred simultaneously with or earlier than the delta wave during sinus rhythm with manifest preexcitation；and (3 atrial activation occurred simultaneously with or earlier than that recorded in the reference coronary sinus electrogram during retrograde AP conduction. Succeccful criteria was complete loss of anterograde and retrograde AP conduction. * 본 연구는 1995년도 연세대학교 의과대학 과별 project 연구비 지원에 의한 결과임.