Accelerated idioventricular rhythm: a benign arrhythmia in childhood

To determine whether accelerated idioventricular rhythm (AIVR) is benign in pediatric patients.

The records were reviewed of all patients younger than age 15 years who had been diagnosed with a ventricular arrhythmia between 1976 and 1991.

AIVR was diagnosed in 12 patients, ages 1 day to 15 years (mean, 8.9 years). In 3 patients the arrhythmia was discovered on ambulatory electrocardiographic monitoring after presentation with syncope or presyncopal symptoms. One patient had palpitations. The remaining diagnoses were made during routine examinations or at postoperative follow-ups for congenital heart disease. The AIVR rate ranged from 90 to 150 beats per minute. The rate was within 10 beats per minute of the preceding sinus rate in 11 patients. Echocardiograms were normal in 8 patients. Two patients had double-outlet right ventricles; 1 had repair of the tetralogy of Fallot; and 1 had abnormal ventricular septal motion. Seven patients were taking antiarrhythmia medication without control of the AIVR at presentation. Patients were followed for a mean of 68.4 months (range, 31 to 191 months). All patients were alive and asymptomatic, with normal activity at the last follow-ups.

Complete resolution of AIVR may not occur. However, AIVR seems to be a benign arrhythmia. Treatment was not effective in controlling the arrhythmia and is likely unnecessary.