“…It occurs almost exclusively in middle-aged patients without structural heart disease, but rare pediatric cases were referred for syncope or near-syncope (Deal et al, 1986;Drago et al, 1999;O'Connor et al, 1996;Pfammater & Paul, 1999;Pfammater, Paul, & Kallfelz, 1995). Its incidence in pediatrics may be estimated around 2,8/1.000.000 childhood years (Roggen, Pavlovic, & Pfammater, 2008) and only 15% of them are symptomatic (Harris et al, 2006). It is generally considered to have an excellent prognosis unless the patient has a history of syncope, very fast tachyarrhythmia or ventricular premature beats with a short coupling interval.…”