If you’re preparing for the United States Medical Licensing Examination® (USMLE®) Step 3 exam, you might want to know which questions are most often missed by test-prep takers. Check out this example from Kaplan Medical, and read an expert explanation of the answer. Also check out all posts in this series.
A 57-year-old woman with diabetes and nephrolithiasis is brought to the emergency department because of chest pain that began when playing with her grandchild. She had a previous myocardial infarction and had a three-vessel bypass two years prior. Her medications include atenolol, lisinopril, allopurinol and atorvastatin daily.
The patient is currently complaining of chest pain and appears uncomfortable. She is diaphoretic and appropriately anxious. Her blood pressure is 190/110 mm Hg and pulse is 110/min. She has an S4 gallop and scant bi-basilar rales. An electrocardiogram shows sinus tachycardia with a left axis deviation. Voltage criteria are met for left ventricular hypertrophy and there are ST-segment depressions of 2.5mm in leads V1-V5.
Which of the following is the most appropriate next step in management?
A. Administer furosemide intravenously
B. Administer morphine intravenously
C. Administer nitroglycerin intravenously
D. Administer verapamil intravenously
E. Obtain a chest radiograph
The correct answer is C.
Kaplan Medical explains why
This patient is having cardiac ischemia in the setting of increased myocardial oxygen demand. She has known coronary disease, and her vital signs at the time of her angina episode show hypertension and tachycardia. The patient must have her blood pressure lowered acutely to the goal of terminating the angina with nitroglycerin.
Why the other answers are wrong
Choice A. Furosemide may work to relieve some pulmonary congestion that this patient has as a result of her ischemia and increased left-sided filling pressures. It however fails to address the primary problem of her increased demand.
Choice B. Morphine is usually given to relieve pain, but nitroglycerin is more important at this time because it can relieve pain and also reduce the underlying ischemia.
