Welcome to MedSmarter’s USMLE Style Question Break Down of the Week. For those preparing for the USMLE Step 1, this week we break down a high-yield Cardiology question. As always you want to begin with reading the last sentence of the vignette first to get an understanding of what the question is asking for.
Question Break Down of the Week:
A 55-year-old man presents to the ED with chest pain. His preliminary workup showed that he was suffering from a severe myocardial infarction. He is initially treated with nitrates, β-blockers, and aspirin, and subsequently undergoes cardiac catheterization with the placement of three stents. Following the procedure, he is hemodynamically stable without recurrence of chest pain. However, 5 days after admission his resting heart rate is 129/min, blood pressure is 70/37 mm Hg, and respiratory rate is 30/min. Physical examination reveals distant heart sounds and jugular venous distension. Which of the following complications is most likely causing this patient’s symptoms?
A) Aneurysm formation
B) Rupture of the papillary muscle
C) Rupture of the ventricular free wall
D) Fibrinous pericarditis
E) Cardiac Arrhythmia
The correct answer is C: This patient is in shock due to cardiac tamponade secondary to the rupture of the ventricular free wall, which usually occurs 3-14 days after the initial myocardial infarction. It usually presents with sudden shock with signs of cardiac tamponades, such as hypotension, distant heart sounds, and jugular venous distension observed in this patient. Survival depends primarily on the rapid recognition of myocardial rupture and the provision of immediate therapy. An urgent pericardiocentesis should be performed or the patient should be immediately prepped for surgery. Unfortunately, this complication of an MI is often a fatal one.
Did you think the answer was different?
Did you think that the correct answer choice was other than C? You can view this video for a deeper discussion of why A, B, D, and E were not the correct answer choices.
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