Clinical characteristics of focal atrial tachycardias arising from the atrial appendages during childhood.

Methods: The study population consisted of 16 consecutive pediatric patients with focal AT enrolled between March 1991 and June 2009. A retrospective analysis was performed. The patients with focal AT were divided into two groups: the AAT group and other AT (OAT) group, in which the foci arose from other atrial sites. Results: Fifty percent had AAT. The AAT patients consisted of more males (88% vs 25%; P < 0.05), were more often asymptomatic at the initial visit (75% vs 25%; P < 0.05), and more often presented with an incessant form of the AT (88% vs 25%; P < 0.05) than the OAT patients. Second-degree atrioventricular block during slow ATs of < 120 beats per minute were more often observed in the AAT patients (63% vs 13%; P < 0.05). The incidence of tachycardia-mediated cardiomyopathy was 19% out of all our subjects and 38% of the AAT patients. Conclusions: The AATs are the major source of focal ATs in pediatric patients that are typically incessant. These characteristics probably explain why a much higher percentage of the patients are presented with TMC. (PACE 2011; 34:177-184).