Radiofrequency catheter modification or elimination of the slow atrioventricular nodal pathway is currently considered the first-line treatment for patients presenting with recurrent symptomatic atrioventricular nodal reentry tachycardia (AVNRT) 1. The slow pathway is commonly localized at the posterior portion of Koch’s triangle2. The effective ablation site is generally targeted by careful mapping of this area, accomplished using a deflectable catheter advanced along the inferior vena cava (IVC). In this report, we describe 2 cases in which a superior vena cava (SVC) approach was utilized to successfully ablate the slow pathway in 2 patients in whom the conventional approach to the target site was either impossible or contraindicated owing to congenital (case 1) and acquired (case 2) disease of the IVC.