A 27-Year-Old Woman Is Brought to the Emergency Department Due

A 27-year-old woman is brought to the emergency department due to a 4-hour history of chest pain that is localized to the middle of the chest and the upper sternal area.  She describes it as "intense."  The patient has never before experienced a similar pain.  She also describes some nausea and a mild occipital headache.  She has had no vomiting, abdominal pain, or shortness of breath.  A friend who accompanies her to the emergency department says that they attended a party and the patient smoked crack cocaine shortly prior to her episode of chest pain.  She did not consume alcohol.  The patient has a history of intravenous drug use.  She was treated with antibiotics for upper extremity cellulitis 6 months ago.  There is no family history of premature coronary artery disease.  The patient does not take any medications and has no known drug allergies.  On initial evaluation, temperature is 37.8 C (100 F) , blood pressure is 204/102 mm Hg on the right arm and 210/104 mm Hg on the left arm, pulse is 102/min and regular, and respirations are 18/min.  Oxygen saturation is 99% on room air.  The patient appears thin, anxious, and agitated.  Heart sounds are normal and no murmurs are heard.  Lungs are clear to auscultation bilaterally.  The abdomen is soft and nontender.  Lower extremity pulses are full and symmetric.  There is no peripheral edema.  ECG shows sinus tachycardia but is otherwise unremarkable.  Portable chest x-ray reveals clear lung fields.  Finger-stick blood glucose level is 98 mg/dL.
Which of the following is the most appropriate next step in management of this patient?

A) Aspirin and clopidogrel
B) Intravenous lorazepam
C) Intravenous metoprolol
D) Intravenous phentolamine
E) Low-molecular-weight heparin