SUMMARY
Incessant focal atrial tachycardia (FAT) is the most common cause of tachycardia-induced cardiomyopathy in pediatric patients and is usually a reversible condition with effective management of tachycardia, either with medical treatment or ablation. These patients may be misdiagnosed, potentially leading to inappropriate treatment. Diagnosis is often late and should always be suspected in patients with congestive heart failure and unexplained persistent tachycardia. Para-Hisian atrial tachycardia is not an uncommon type of FATs; however, catheter ablation of anterior atrial septum-ATs has been a challenge because of its proximity to the AV node and the complex anatomy of its region.