[Tachycardiac arrhythmia in children without congenital heart diseases].

Based on invasive electrophysiological studies and ablation procedures of tachycardias in children and adolescents, the understanding and knowledge of the different tachycardia substrates have significantly increased in recent years. This article describes the underlying pathophysiological mechanisms together with the expected changes in electrocardiogram (ECG) of the four most common types of supraventricular tachycardia in children and adolescents without congenital heart defects: atrioventricular reentrant tachycardia, atrioventricular nodal reentrant tachycardia, focal atrial tachycardia and permanent junctional reentrant tachycardia. Furthermore, idiopathic ventricular tachycardia is described. The incidence, clinical symptoms, natural course and prognosis of each particular tachycardia will be specified . The pharmacological and interventional treatment will be the focus of other reports in this issue. Finally, the current recommendations for the approach to asymptomatic children and adolescents with preexcitation are discussed according to the current guidelines.