USMLE Forum Archives - USMLE Step 1 - cp1
cp1
babbu5508 - 03-25-11 11:54
A 45-year-old man presents to the emergency department complaining of chest pain, which began twenty minutes before while he was filling
up his car with gasoline. He describes the pain as substernaI, intense, dulI, and squeezing. It does not change with respiration. He also
complains that he is nauseated. He has never experienced anything like this before. His temperature is 37.5 C (99.5 F), blood pressure is
124/76 mm Hg, pulse is 80/min, respiratory rate is 22/min, and oxygen saturation is 95% on room air. On physical examination, he is
diaphoretic. His lungs are clear, his heart rate is regular, and he has a normaI S1 and S2 without murmur, rub, or gallop. The examiner
estimates that his jugular venous pressure is elevated to the angle of the jaw. His abdomen is nontender, with normal bowel sounds. An
electrocardiogram is performed, which reveals sinus rhythm, normal axis, normal intervals, and ST elevation in leads lI, III, and aVF. A chest x-
ray film reveals no apparent cardiac or pulmonary abnormalities.
Which of the following is the most likely diagnosis?
/ A. Acute myocardial infarction
/ B. Aortic dissection
/ C. Gastroesophageal reflux
/ D. Pericarditis
/ E. Pulmonary embolus
babbu5508 - 03-25-11 11:54
A 45-year-old man presents to the emergency department complaining of chest pain, which began twenty minutes before while he was filling
up his car with gasoline. He describes the pain as substernaI, intense, dulI, and squeezing. It does not change with respiration. He also
complains that he is nauseated. He has never experienced anything like this before. His temperature is 37.5 C (99.5 F), blood pressure is
124/76 mm Hg, pulse is 80/min, respiratory rate is 22/min, and oxygen saturation is 95% on room air. On physical examination, he is
diaphoretic. His lungs are clear, his heart rate is regular, and he has a normaI S1 and S2 without murmur, rub, or gallop. The examiner
estimates that his jugular venous pressure is elevated to the angle of the jaw. His abdomen is nontender, with normal bowel sounds. An
electrocardiogram is performed, which reveals sinus rhythm, normal axis, normal intervals, and ST elevation in leads lI, III, and aVF. A chest x-
ray film reveals no apparent cardiac or pulmonary abnormalities.
Which of the following is the most likely diagnosis?
/ A. Acute myocardial infarction
/ B. Aortic dissection
/ C. Gastroesophageal reflux
/ D. Pericarditis
/ E. Pulmonary embolus
The correct answer and explanation will be available after you answer.
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#2
Re: cp1
babbu5508 - 06-30-11 23:19 The correct answer is A. The differential diagnosis of chest pain is broad and includes all the answers on this list, all of which can present, as in this patient, with a relatively normal examination of the heart and lungs. Acute myocardial infarction is the only one of these findings that is associated with ST segment elevation in an anatomical distribution (in this case, the "inferior" leads). His elevated jugular venous pressure is also a clue to abnormal cardiac function; however, this might be present in severe
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