In a sentinel study from 1985 on AFL in the young with limited diagnostic methods available at that time, less then 10% of the patients had an “otherwise” normal heart (“lone AFL”). Beyond this age, AFL primarily occurs in the presence of congenital heart disease (CHD), in patients with accessory atrioventricular (AV) pathways, in myocarditis and in patients with various types of cardiomyopathy. In pediatric patients, atrial flutter (AFL) without any obvious cardiac abnormatility (“lone AFL”) is rare and most frequently occurs in the neonatal period. EMB was very helpful in order to timely establish the diagnosis of myocarditis or cardiomyopathy. EMB and clinical course revealed an underlying cardiac pathology in the majority of the individuals studied. Our study demonstrates that true “lone AFL” in children and adolescents is rare. Taking together results of EMB and further clinical course, only 3/8 patients finally turned out to have true “lone AFL”. The remaining patient with recurrent arrhythmia had a negative EMB but was diagnosed with Brugada syndrome during further follow-up. 3/4 patients with recurrent arrhythmia had pathological EMB results. During follow-up, 4/8 patients had recurrent arrhythmia (AFL n = 2, wide QRS complex tachycardia n = 1, monomorphic premature ventricular contractions n = 1) after the ablation procedure. Histopathological examination of EMB from the right ventricular septum exhibited myocarditis or cardiomyopathy in 4/6 patients, respectively. Induction of CTI conduction block was achieved in all patients. Since July 2005, eight consecutive patients at a median age of 12.7 (range 10.4–16.7) years presenting with presumed “lone AFL” after negative non-invasive diagnostic work-up had electrophysiological study (EPS) and induction of cavotricuspid isthmus (CTI) conduction block by radiofrequency (RF) current application. Our study aims to present clinical and electrophysiological data of presumed “lone AFL” in pediatric patients and discuss the role of endomyocardial biopsy (EMB) and further follow-up. Atrial flutter (AFL) in children and adolescents beyond the neonatal period in the absence of any underlying myocardial disease (“lone AFL”) is rare and data is limited.

Atrial flutter ablation lenox