Catheter Ablation of Accessory Pathways

Abstract

Patients who have either the Wolff-Parkinson-White syndrome or a concealed accessory atrioventricular (AV) connection may be appropriate candidates for nonpharmacologic treatment for one or more of the following reasons: 1) the occurrence of rapid and potentially life-threatening tachycardias, for example, atrial fibrillation with a ventricular rate of 250 beats/ minute, associated with loss of consciousness or a cardiac arrest; 2) inefficacy of antiarrhythmic drugs; 3) intolerance to antiarrhythmic drugs; or 4) patient preference. Up until the recent past, if it was decided that a patient was an appropriate candidate for definitive therapy, surgery provided the only means by which an accessory AV connection could be ablated. However, the transcatheter ablation technique now provides a potential alternative to surgical ablation of at least some types of accessory AV connections. This chapter shall review the current status of transcatheter ablation of post-eroseptal, left free-wall, and right free-wall accessory AV connections. Because the largest amount of experience and the highest success rate has been reported for accessory AV connections that are posteroseptal in location, this type of accessory AV connection will be discussed first.