Aortic Dissection 1

Question

Vignette:

A 50-year-old male presents to the emergency department with sudden onset of severe chest pain radiating to the back. His blood pressure is 150/90 mmHg and heart rate is 100 beats per minute. On physical examination, he is in severe distress. Cardiac enzymes are normal. CT scan of the chest shows an abnormal widening of the mediastinum. Which of the following is the most likely diagnosis?

Choices

A. Myocardial infarction

B. Dissecting aortic aneurysm

C. Pulmonary embolism

D. Pneumothorax

E. Pericarditis

Answer

B. Dissecting aortic aneurysm

Explanation

The patient's history of hypertension, acute onset of severe chest pain radiating to the back, and the CT finding of an abnormal widening of the mediastinum are classic for a dissecting aortic aneurysm. This is a life-threatening condition in which blood enters the medial layer of the aortic wall through a tear or ulcer in the intima, causing separation of the layers of the aortic wall (dissection) and formation of a false lumen. The pain is typically described as "tearing" or "ripping", and the widened mediastinum seen on chest imaging is due to the presence of blood dissecting into the aortic wall. Cardiac enzymes are typically normal because this is not a myocardial infarction. This condition must be rapidly diagnosed and managed to prevent catastrophic complications such as rupture and death. Other choices, while they can cause chest pain, do not fit with the clinical picture and imaging findings in this case.