COINCIDENT IDIOPATHIC LEFT-VENTRICULAR TACHYCARDIA AND ATRIOVENTRICULAR NODAL REENTRANT TACHYCARDIA - CONTROL BY RADIOFREQUENCY CATHETER ABLATION OF THE SLOW ATRIOVENTRICULAR NODAL PATHWAY

A healthy 37-year-old male presented with a history of frequent palpit ations and sustained wide QRS complex tachycardia with a right bundle branch block and left axis morphology. Serial electrophysiological stu dies revealed two inducible tachycardias, which were shown to represen t atrioventricular nodal reentrant tachycardia and idiopathic left ven tricular tachycardia. Transformation from one tachycardia to the other occurred spontaneously as well as following atrial or ventricular pac ing. Radiofrequency catheter ablation of the slow atrioventricular nod al pathway resulted in cure of atrioventricular nodal reentrant tachyc ardia and the prevention of spontaneous recurrence of ventricular tach ycardia, suggesting a role of atrioventricular nodal reentrant tachyca rdia in triggering the clinical episodes of ventricular tachycardia. T he patient has remained asymptomatic without antiarrhythmic therapy fo r 8 months.