Weathering an Adenosine-Insensitive Right Ventricular Outflow Tract Ventricular Tachycardia Storm in an Adolescent Female: A Case Report

Abstract

Majority of ventricular tachycardias (VT) are associated with structural disease. However, 10% are idiopathic, such as right ventricular outflow tract (RVOT) VT. A vast majority of RVOT VT demonstrates sensitivity to adenosine, consistent with a triggered mechanism. We present the case of a 15-year-old female patient with palpitations, lightheadedness and dyspnea and a past history of a similar episode of incessant palpitations a month ago, which necessitated electrical cardioversion and amiodarone. On admission, a wide complex tachycardia was documented. Detailed analysis of her wide complex tachycardia showed left bundle branch block (LBBB) morphology, atrioventricular dissociation and positive QRS complexes in inferior leads, suggestive of RVOT VT storm. The patient’s arrhythmia was not responsive to adenosine; hence, adenosine-insensitive RVOT VT was considered. Synchronous cardioversion terminated the tachyarrhythmia. On electrophysiological studies, the VT was induced and localized at the RVOT via 3D-electroanatomical mapping. Radiofrequency ablation of the focus was performed, immediately terminating the tachycardia. The patient was discharged well.