Review Question - QID 211058

A 67-year-old man presents to the emergency department with crushing substernal chest pain and shortness of breath that started 2 hours ago. He has a past medical history significant for morbid obesity and type II diabetes mellitus. He states that he is poorly compliant with his prescribed medications. His temperature is 98.1°F (36.7°C), blood pressure is 137/98 mm Hg, pulse is 100/min, respiratory rate is 24/min, and oxygen saturation is 100% on room air. Exam reveals an uncomfortable-appearing, diaphoretic man in acute distress. An electrocardiogram is obtained as shown in Figure A. As the patient is being assessed and stabilized, he suddenly becomes unresponsive. He is noted to be pulseless and apneic. Chest compressions are initiated. Which of the following is the most likely cause of this patient's cardiac arrest?