A 45-year-old man had coronary artery stents placed 2 days ago. Today, he is in severe distress and is reporting “crushing” chest discomfort. He is pale, diaphoretic, and cool to the touch. His radial pulse is very weak, blood pressure is 64/40 mm hg, respiratory rate is 28 breaths/min, and oxygen saturation is 89% on room air. When applied, the cardiac monitor initially showed ventricular tachycardia, which then quickly changed to ventricular fibrillation. If the lidocaine doent work what drug do you give next?