*For rhythms that break or recur spontaneously, synchronized cardioversion is not appropriate. AVRT indicates atrioventricular reentrant tachycardia; ECG, electrocardiogram; and IV, intravenous. Page et al 2015 ACC/AHA/HRS SVT Guideline e545 8.2. Ongoing Management: Recommendations 9. Special Populations As discussed in the Scope (Section 1.4), the present docu- ment is aimed at the adult population ( 18 years of age) and offers no specific recommendations for pediatric patients. Nevertheless, a brief discussion of SVT in pediatric patients is included below, highlighting major considerations with regard to SVT in younger patients, including adolescent patients. SVT in young patients varies significantly from SVT in adult patients in terms of mechanism, risk of developing heart failure or cardiac arrest, risks associated with inter- ventional therapy, natural history, and psychosocial impact. Approximately half of pediatric SVT presents in the first 4 months of life, with age-related peaks in occurrence subse- quently at 5 to 8 years and after 13 years. Accessory pathway mediated tachycardia accounts for >70% of SVT in infants, decreasing to approximately 55% in adolescents.56,407 409 AVNRT increases with age, from 9% to 13% of SVT in infants, to 30% to 50% of SVT in teenagers. After 12 years of age, women are more likely to have AVNRT than men, and overall SVT is less frequent among African American and Hispanic patients than in the general pediatric population.56 Atrial flutter is seen in some neonates and in older children is predominantly observed after congenital heart disease. AF is uncommon in childhood, accounting for <3% of supraven- tricular arrhythmias, and may be a consequence of AVRT or AVNRT in adolescents or may be associated with repaired congenital heart disease. Symptoms of SVT vary with age: gastrointestinal or respiratory findings in infants, chest or abdominal pain in the younger child, and palpitations in the adolescent. 