Transcatheter Modulation of Atrioventricular Nodal Conduction by Radiofrequency Current

A new technique is presented in which atrioventricular (A V) nodal conduction properties can be altered in a controlled way through the application of radiofrequency current. In 13 patients with supraventricular arrhythmias (maximal heart rate 215/min) radiofrequency current was delivered to the A V node via a catheter. Nine patients had atrial fibrillation, three had A V nodal reentrant tachycardia, and one patient had accessory pathway mediated A V tachycardia. Radiofrequency current application in these patients increased AV nodal conduction time and antegrade A V nodal effective refractory period significantly. In three patients radiofrequency current had no effect, and the A V node was ablated with direct current shocks. During a mean follow-up period of 10 ± 3 months, all ten patients in whom radiofrequency current application had been successful were asymptomatic without antiarrhythmic medication. No complications were observed, neither during nor after the procedure.