Is the Mechanism of Supraventricular Tachycardia in Pediatrics Influenced by Age, Gender or Ethnicity?

Background. The mechanism of supraventricular tachycardia (SVT) in adults is influenced by age and gender. The purpose of this study was to determine whether age, gender, or ethnicity impact the mechanism of SVT in pediatric patients.

Methods. A search of the Pediatric Electrophysiology Registry identified patients who had undergone a radiofrequency ablation for SVT from 1999 to 2004. Patients were grouped into categories based on the mechanism of tachycardia, age, gender, and ethnicity. US Census data from 2000 served as a benchmark for expected race and gender distributions.

Results. The study looked at 3556 patients (≤7 years, n = 378; 7–12 years, n = 964; 12–21 years, n = 2214), with 1948 males, 2916 whites, 266 blacks, 248 Hispanics, 63 Asians, and 63 of another ethnicity. For accessory pathways (APs), there were 2418 patients (1405 male), and for atrioventricular node reentry tachycardia (AVNRT), there were 1138 patients (544 male). The APs decreased in proportion with increasing age; conversely, AVNRT increased with increasing age (P < .001). Significant differences were found in gender distribution between APs and AVNRT in the 12–21 years age group, with females more likely to have AVNRT than AP (P < .0001). No significant gender differences were present at younger ages. With respect to ethnicity, APs were more common than AVNRT in the white, black, and Hispanic ethnic groups (P < .02). When comparisons were made between ethnic groups from our registry and US Census data, whites had a much higher frequency of SVT than their representation in the US population (85% vs. 68.7%), while blacks (8.7% vs. 15%) and Hispanics (5.6% vs. 17.0%) had a lower frequency of SVT than their representation in the US population (P < .0001).

Conclusion. The mechanism of SVT in pediatric patients is associated with age, gender, and ethnicity. The proportion of SVT due to APs decreases as age increases. Among children older than 12 years, females are more likely than males to have AVNRT as the mechanism of tachycardia. The racial distribution of patients in the registry differs from that of the US population, with a greater proportion of whites seen in the registry.