Fascicular Tachycardia

Ventricular arrhythmias involving the fascicular conduction system can be seen in both structurally normal and abnormal hearts. The morphology of QRS complexes on the electrocardiogram during tachycardias are a good tool to identify the likely site of origin of such a rhythm. Although these arrhythmias generally carry a relatively benign prognosis, sudden death events have been reported, which fortunately are rare, since most of these tachycardias occur in the young population. Idiopathic fascicular ventricular tachycardia (IFVT) represents, among all forms of idiopathic ventricular tachycardias (RV or LV outflow tract tachycardias, papillary muscle tachycardias) about 10% to 15% of cases.