SUCCESSFUL SLOW PATHWAY ABLATION IN A PATIENT WITH ATRIOVENTRICULAR NODAL REENTRANT TACHYCARDIA HAVING A PROXIMAL COMMON PATHWAY

Radiofrequency catheter ablation was attempted in a patient with atrio ventricular nodal reentrant tachycardia (AVNRT). AVNRT tl as easily in ducible but an intermittent loss of the atrial activation was observed during AVNRT suggesting the presence of a proximal common pathway. Du ring sinus rhythm, a relatively delayed activation that was compatible with a slow potential, was recorded anterior to the ostium of coronar y sinus, and radiofrequency catheter ablation application (20 watts) t o the site induced junction tachycardia. After an additional radiofreq uency catheter ablation application to close the site, AVNRT became no ninducible without deterioration of atrioventricular conduction throug h a fast pathway. This is the first case in which radiofrequency cathe ter ablation application to the slow potential recording site has been successful, even in AVNRT having a proximal common pathway.