Pediatric Cardiology and Cardiac Surgery
Vol.27 No.1 2011 (11-17)

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Keiko Toyohara, Jun Yoshimoto, Noriyasu Ozaki, Hitoo Fukuhara, and Yoshihide Nakamura

Department of Pediatric Cardiology, Japanese Red Cross Society, Wakayama Medical Center, Wakayama, Japan


Background: Most children with supraventricular tachycardia (SVT) and WPW syndrome experience their initial episode by one year of age. Although most patients’ conditions resolve within one year, SVT recurs in 40%.
Objective: We determined the prognosis of children with WPW syndrome who experienced their initial episode of SVT before one year of age.
Method: We reviewed the clinical courses of 36 patients with WPW syndrome without congenital heart disease.
Results: All the patients underwent electrophysiological studies (EPS). In four cases, ventriculoatrial conduction disappeared or lengthened during EPS performed at one year of age (group A). In five cases, we induced SVT during the EPS at one year of age (group B). Nine cases had drug-resistant tachycardia or severe heart failure during infancy (group C). In 11 cases, SVT disappeared before three months of age, but it recurred after five years of age and persisted (group D). Seven cases had recurrent SVT over a long period from its onset (group E). The 32 patients in groups B, C, D, and E (92%) underwent radiofrequency catheter ablation (RFCA). We ablated all the accessory pathways (APs). Even in the patients under two years, the outcome of RFCA was favorable, and there were no complications or recurrences.
Conclusion: In 92% of our cases, the retrograde conductions of APs persisted under two years of age, or after temporary resolution, SVT recurred after five years of age. We recommend that EPS and RFCA be considered for these patients because of the high incidence of SVT.