RADIOFREQUENCY CATHETER ABLATION FOR AV NODAL REENTRANT TACHYCARDIA ASSOCIATED WITH PERSISTENT LEFT SUPERIOR VENA-CAVA

Slow AV nodal pathway ablation using RF is highly effective for patien ts with refractory AV nodal reentrant tachycardia (AVNRT). We report t hree catheter ablation cases using RF current in patients associated w ith persistent left superior vena cava (PLSVC). Three patients with dr ug refractory AVNRT of common variety were involved in this study. An electrode catheter introduced through the left subclavian vein inserte d directly into the coronary sinus, a typical anatomical finding of PL SVC. The ablation procedure was initially performed at the posteroinfe rior region of Koch's triangle. A slow pathway potential could not be found from that area; nonsustained junctional tachycardia (NSJT) did n ot occur during the delivery of RF current; there was failure to elimi nate slow AV nodal pathway conduction. The catheter then was moved int o the bed of the proximal portion of the markedly enlarged coronary si nus. A slow AV nodal pathway potential was recorded through the ablati on catheter, and the delivery of RF current ca used NSJT in two patien ts. Complete elimination of slow AV nodal pathway conduction was accom plished in these two patients by this method. No adverse effects were provoked by this procedure. Catheter ablation of the slow AV nodal pat hway guided by a slow pathway potential and the appearance of NSJT was feasible and safe in the area of the coronary sinus ostium in patient s associated with PLSVC.