Electrocardiographic features, mapping and ablation of idiopathic outflow tract ventricular arrhythmias

Purpose: Idiopathic outflow tract ventricular arrhythmias are ventricular tachycardias or premature ventricular contractions presumably not related to myocardial scar or disorders of ion channels. These arrhythmias have focal origin and display characteristic electrocardiographic features. The purpose of this article is to review the state of the art of diagnosis and treatment of idiopathic outflow tract ventricular arrhythmias. Methods: We systematically reviewed scientific literature about idiopathic outflow tract ventricular arrhythmias selecting the most relevant papers on this topic. Results: The right ventricle outflow tract is the most common site of origin for outflow tract ventricular arrhythmias, but also left ventricle outflow tract can harbour these arrhythmias. Outflow tract ventricular arrhythmias are generally benign and may require treatment if they are symptomatic, incessant or give rise to cardiomyopathy. Radiofrequency catheter ablation is an effective and safe therapeutic strategy. A successful procedure requires a thorough preoperative analysis of the 12-lead electrocardiogram of the spontaneous arrhythmia combined with a detailed electroanatomical mapping and intracardiac echocardiography. Conclusions: Idiopathic outflow tract arrhythmias are frequent in daily clinical practice and can be successfully eliminated through discrete radiofrequency catheter ablation with low rates of complications.