A 55-year-old man with a history of hypercholesterolemia and symptomatic premature ventricular complexes treated with a β-blocker was admitted to an outside hospital with acute-onset left-sided chest pressure, palpitations, and lightheadedness. Paramedics at the scene obtained a 12-lead electrocardiogram (ECG) revealing a wide-complex tachycardia at 248 beats per minute (Figure 1), which self-terminated as the patient was being prepared for direct-current cardioversion. The patient was then treated with chewable aspirin and intravenous lidocaine.