Paroxysmal Nodal Reentrant Tachycardia

In a patient with repetitive disabling tachycardias refractory to pharmacologic treatment, the electrophysiologic study suggested the existence of atrioventricular nodal reciprocating tachycardia. During ventricular pacing, endoepicardial mapping of the lower atrium showed the atrial breakthrough point in an area of the lower interatrial septum close to the AV node crista. A selective atriotomy was performed. The postoperative electrophysiologic studies showed absence of ventriculoatrial conduction at several ventricular pacing rates, while antegrade conduction is preserved. The patient remained free of arrhythmias 21 months after surgery, taking no antiarrhythmic drugs.