[Transient loss of preexcitation by acute coronary ischemia--a case report]

We present a case of WPW syndrome with an accessory pathway in the right free wall. Two prolonged and failed attempts at radiofrequency catheter ablation of this accessory pathway in other institutions led to a third attempt in our hospital. With a 7F catheter in the right coronary artery, transient ischemia in the right ventricular myocardium developed with consecutive loss of bidirectional preexcitation within 45 seconds prior to catheter ablation. Removal of the guiding catheter, while the mapping catheter in the coronary artery was still in place, was reproducibly followed by the reoccurrence of the preexcitation pattern. Successful outcome of accessory pathway ablation was achieved by mapping the right free wall using an intracoronary catheter in the right coronary artery and ablating the accessory pathway using a modified long vascular sheet.