A 58-year-old male presents with the sudden onset of excruciating pain. He describes the pain as beginning in the anterior chest, radiating to the back, and then moving downward into the abdomen. His blood pressure is found to be 160/110. Your differential diagnosis includes myocardial infarction; however, no changes are seen on ECG, and you consider this to be less of a possibility. You obtain an x-ray of this patient’s abdomen and discover a “double-barrel” aoa. This abnormality most likely results from

**Core Concept**
The patient's presentation of sudden onset chest pain radiating to the back and abdomen, along with hypertension, suggests a possible aortic dissection or rupture. The "double-barrel" aorta seen on the abdominal x-ray is indicative of an abdominal aortic aneurysm (AAA), a condition where the aorta dilates, potentially leading to aortic dissection or rupture.

**Why the Correct Answer is Right**
A double-barrel aorta is a characteristic radiographic finding of an abdominal aortic aneurysm. The aortic dilatation creates two lumens, giving the appearance of a "double-barrel" on the x-ray. This occurs due to the weakening of the aortic wall, often as a result of atherosclerosis, hypertension, or other vascular diseases. In this patient, the sudden onset of pain and hypertension may be indicative of an impending aortic dissection or rupture.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the patient's presentation of a double-barrel aorta on abdominal x-ray.

**Option B:** This option is incorrect as it does not relate to the patient's condition of a double-barrel aorta.

**Option D:** This option is incorrect as it does not describe the patient's condition of an abdominal aortic aneurysm.

**Clinical Pearl / High-Yield Fact**
A "double-barrel" aorta is a classic radiographic finding of an abdominal aortic aneurysm, which requires prompt surgical intervention to prevent aortic dissection or rupture.

**Correct Answer:** D. Abdominal aortic aneurysm.

✓ Correct Answer: D. Loss of elastic tissue in the media