Dual atrioventricular nodal non-reentrant tachycardia in a child undergoing repair of ventricular septal defect.

Paroxysmal non-reentrant supraventricular tachycardia due to double ventricular response through antegrade dual atrioventricular nodal pathways by a single atrial excitation has been reported in limited adult cases but not in pediatric patients with structurally normal hearts or with congenital heart defects. We report the case of a 5-year-old boy with non-reentrant double-ventricular response (DVR) supraventricular tachycardia (SVT) after repair of ventricular septal defect. To the best of our knowledge, this is the first pediatric report about an electrophysiologic study and successful selective radiofrequency (RF) catheter ablation for the slow pathway leading to tachyarrhythmia that is difficult to manage medically. In conclusion, non-reentrant DVR SVT is a rare form of tachycardia that should be considered in the differential diagnosis of SVT in children after repair of congenital heart diseases. It is amenable to mapping and RF catheter ablation.