Twenty patients (aged 20 to 71 years, thirteen of them females), presented recurrent and refractory nodal reentry tachycardia (NRT) and were submitted to surgical treatment. The preoperative electrophysiological studies demonstrated classical NRT. All the patients had ventricular-atrial interval of less than 40 milliseconds, and the atrial retrograde depolarization started in the anterior portion of the A-V node. Additionaly, the patients presented retrograde atrial capture phenomenon, suggesting participation of atrio-nodal or atrio-Hisian anomalous pathways. The intraoperative mapping performed during ventricular pacing demonstrate retrograde atrial depolarization starting at the posterior area of the A-V node. The surgical procedure consisted in dissection of the posterior portion of the A-V node with a similar technique used in ablation of postero-septal anomalous pathways, taking care to preserve the Todaro tendon. No intra-nor-postoperative complications were observed. The programmed stimulation performed around the 15th postoperative day was unable to induce NRT. Five to 36 months after the procedure, the patients are asymptomatic with normal A-V conduction and without use of antiarrhythmic drugs. Notwithstanding the small number of cases and the ralatively short follow-up, the surgical procedure appears efficient to control NRT, while preserving intact A-V conduction.
nodal reentry tachycardia