Catheter Ablation of Idioventricular Ventricular Tachycardia Originating from the Aortic Sinus Cusp

Abstract

Ventricular tachycardia (VT) is usually observed in patients with structural heart disease. However, in 10% of the patients presenting with VT, the routine diagnostic modalities demonstrate no myocardial damage. This arrhythmia has been identified as an idiopathic ventricular tachycardia (IVT), and is commonly observed in young patients. Recent studies delineated the mechanisms and anatomical locations responsible for these VTs. Recognition of the various forms of idiopathic VTs is based on the characteristic QRS morphologies observed in the 12-lead electrocardiogram (ECG). A greater understanding of the sites of origin of the idiopathic VTs has led to the increasing success rate of the catheter ablation of these VTs. On the surface ECG, an IVT from the aortic sinus cusp (ASC) has a QRS morphology similar to that of right ventricular outflow tract (RVOT) arrhythmias. This similarity often obscures the origin of the VT. We reported 1 case of an IVT which originated from the aortic cusp.