A man in his late 40s presented to the emergency department with recurrent palpitation and dizziness. He denied having any chest pain or any history of smoking, drug abuse, or alcohol use. His father had died suddenly in his late 30s. While undergoing the workup in the emergency department, he developed wide complex tachycardia (WCT) (Figure 1). He was given intravenous amiodarone. However, the WCT persisted, and he became hypotensive, requiring cardioversion to restore sinus rhythm. His baseline electrocardiographic (ECG) findings during sinus rhythm are shown in Figure 2.