RADIOFREQUENCY CATHETER ABLATION OF ATRIOVENTRICULAR NODAL REENTRY TACHYCARDIA UTILIZING NONFLUOROSCOPIC ELECTROANATOMICAL MAPPING

The advent of catheter ablation stimulated extensive research into ana tomical localization of the pathways involved in atrioventricular noda l reentrant tachycardia (AVNRT). Conventional electrophysiological met hods that attempt to correlate intracardiac electrograms with two-dime nsional fluoroscopic anatomy are limited by the relative inaccuracy an d poor reproducibility of this technique, and the requirement for high levels of radiation exposure. A new method of nonfluoroscopic electro anatomical mapping utilizes magnetic field sensing with a specialized catheter to construct three-dimensional electroanatomical endocardial maps of selected heart chambers with spatial resolution of < 1 mm. Thi s system can be used in patients undergoing catheter ablation for AVNR T to create accurate maps of Koch's triangle and to guide application of radiofrequency energy. Initial experience in 14 patients suggests e fficacy and safety comparable to conventional mapping and ablation tec hniques. Further evaluation may confirm the potential benefits of this system with respect to success rates, complications, procedure time, and radiation exposure.