Follow-up of children or teenagers with paroxysmal supraventricular tachycardia, but without pre-excitation syndrome.

Background: Paroxysmal supraventricular tachycardia (SVT) is considered benign in children if the electrocardiogram in sinus rhythm is normal, but causes anxiety in parents, children and doctors.

Aims: To report on the clinical and electrophysiological data from children with SVT, their follow-up and management.

Methods: Overall, 188 children/teenagers (mean age 15±2.8 years) with a normal electrocardiogram in sinus rhythm were studied for SVT, and followed for 2.3±4 years.

Results: SVT was poorly tolerated in 30/188 children (16.0%). SVT was related to atrioventricular nodal reentrant tachycardia (AVNRT) (n=133) or atrioventricular reentrant tachycardia (AVRT) over a concealed accessory pathway (n=55; 29.3%). Ablation of the slow pathway (n=66) or the accessory pathway (n=43) was performed without general anaesthesia, 2±3 years after initial evaluation. Failure or refusal to continue occurred in 18/109 (16.5%) children: 7/66 with AVNRT (10.6%), 11/43 with AVRT (25.6%) (P<0.001). Symptoms of SVT recurred in 20/91 children (22.0%) with apparently successful ablation: 6/91 (6.6%) had real SVT recurrence; 14/91 (15.4%) had only a sinus tachycardia, more frequent in AVNRT (11/59; 18.6%) than AVRT (3/32; 9.4%) (P<0.05). In 13 children treated with an antiarrhythmic drug (AAD), SVT recurred in four; two presented AAD-related syncope. In 66 untreated children, one death was noted after excessive AAD infusion to stop SVT; the others remained asymptomatic or had well-tolerated SVT.

Conclusions: At the time of ablation, SVT management remains difficult in children. Indications for ablation are more common in AVRT than in AVNRT, but failures are frequent; 22.0% remained symptomatic after successful ablation, but false recurrences were frequent (15.4%). Without ablation, one third had a spontaneous favourable evolution.