Review Question - QID 206388

A 62-year-old lady is brought to the emergency department by ambulance following a high speed motor vehicle accident. On arrival
she is alert and responsive and complains of non-radiating chest pain. She also reports shortness of breath and nausea. Her past medical history is significant for hypertension and hyperlipidemia, for which she takes hydrochlorothiazide and simvastatin. Her temperature is 37 C, heart rate 98/min, blood pressure 86/52 mm Hg, respiratory rate 16/min, and SpO2 98% on room air. On physical exam, she has multiple bruises over the chest, and there is exquisite tenderness over the sternum. Upon palpation of the sternum, you feel crunching and crepitation. Cardiac auscultation reveals a regular rate and rhythm with no murmurs, rubs, or gallops. Jugular venous pressure is slightly elevated. An electocardiogram (ECG) (Figure A) and chest radiograph (Figure B) are performed. An ECG from a prior visit is shown in Figure C. Her blood pressure does not improve following a one-liter bolus of lactated Ringer's solution. What is the most likely diagnosis? ...