**5. Work-up/diagnosis**

In chronological order as the patient is admitted into ER with a clinical picture suggestive of aortic dissection:

### **5.1 Electrocardiography**

ECG changes may mimic acute cardiac ischemia, which make it further difficult to distinguish aortic dissection from acute myocardial infarction in the presence of chest pain.

If the dissection involves the coronary ostia, the right coronary artery can be affected, which will lead to ST segment elevation in a similar pattern to inferior wall infarction.

In most cases, there will be non-specific ECG changes, or ECG can be normal.

## **5.2 Blood investigations**

CBC: there may be **leukocytosis** due to stress state. **Low hemoglobin** and hematocrit suggests bleeding (dissection is leaking or has ruptured).

**Elevated creatinine and BUN** may indicate involvement of renal arteries (in such scenario you would expect hematuria, oliguria, or anuria), or it may indicate dehydration due to pre-renal blood loss (dissection is leaking or has ruptured).

**Troponin I and T may be elevated** if the dissection has involved the coronary arteries and caused myocardial ischemia.

LDH (lactate dehydrogenase) may be elevated due to hemolysis in the false lumen. D dimer: high negative predictive value. **Aortic dissection is less likely if D dimer is negative** [15].
