Differential Diagnosis for Chest Discomfort

The patient presents with chest discomfort that worsened over time, accompanied by nausea, diaphoresis, and an elevated ST troponin level. Given these symptoms and test results, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Acute Myocardial Infarction (MI): The patient's symptoms of chest discomfort, nausea, diaphoresis, and significantly elevated troponin levels are highly suggestive of an acute MI. The fact that the discomfort started intermittently and then became more severe also aligns with the typical presentation of a myocardial infarction, especially in a smoker.

• Other Likely Diagnoses

  • Acute Coronary Syndrome (ACS): While ACS is a broader category that includes MI, unstable angina, and other conditions, the elevated troponin levels in this patient make MI the more specific diagnosis within ACS. However, the initial presentation could be considered under the ACS umbrella.
  • Pulmonary Embolism (PE): Although less likely given the elevated troponin, PE can cause chest discomfort and nausea. The absence of mentioned risk factors for PE (e.g., recent travel, immobilization, family history of clotting disorders) makes it less likely but still a consideration.

• Do Not Miss Diagnoses

  • Aortic Dissection: This is a life-threatening condition that can present with sudden, severe chest pain and could potentially lead to nausea and diaphoresis. Although the EKG shows a normal sinus rhythm and there's no mention of unequal blood pressures in the arms or a murmur suggestive of aortic regurgitation, aortic dissection is a "do not miss" diagnosis due to its high mortality rate if not promptly treated.
  • Cardiac Tamponade: Another potentially life-threatening condition, cardiac tamponade can cause chest discomfort, nausea, and diaphoresis. It might be considered if there were signs of heart failure or a significant pericardial effusion, though these are not mentioned.

• Rare Diagnoses

  • Myopericarditis: This condition involves inflammation of the heart muscle and the sac surrounding the heart (pericardium). It can cause chest pain and elevated troponin levels but typically presents with a more gradual onset and might be accompanied by a pericardial friction rub on physical examination.
  • Spontaneous Coronary Artery Dissection (SCAD): A rare cause of acute coronary syndrome, SCAD can occur without the typical risk factors for coronary artery disease. It's more common in women but can occur in men, especially those with a history of hypertension or extreme physical exertion.