A 58 year old male with a history of hypertension and diabetes presents to the emergency room with chest pain at rest. He states the pain is substernal, pressure-like, and associated with diaphoresis and shortness of breath. He is afebrile, blood pressure is 110/70, heart rate 70, and respirations 18. Physical examination reveals normal lung sounds, normal jugular venous pressure, and an S4 heart sound. Laboratory studuies are initially normal. His ECG is below. What is the appropriate diagnosis?
A. Unstable angina with anterior ischemia
B. Posterior wall myocardial infarction
C. Inferior wall myocardial infarction
D. Non-cardiac chest pain