Aortic Dissection: Field Suspicion
Objective: Suspect dissection from the story before you treat the pain as ACS. Hold aspirin and nitro until the picture is clear. Choose a hospital that can repair an aorta.
Why this matters
Aortic dissection can feel like a STEMI. STEMI means an ST-elevation heart attack. The 12-lead can even show one if the tear involves a coronary artery. Aspirin and nitro are the usual ACS habit. ACS means a heart-attack workup. If this is dissection, nitro can drop the blood pressure that is still moving blood through the torn aorta.
Clinical sequence
- If the pain is sudden, tearing, or ripping, or if chest or back pain comes with a stroke-like finding, check blood pressure and pulses in both arms. That is the first check.
- Give oxygen if the sat is low. Hold nitro and aspirin until the picture is ACS, not dissection. Follow protocol and medical control.
- Get a 12-lead anyway. Inferior ST elevation can be ACS, or it can be a torn right coronary artery. The story still decides which one you are treating.
- Go to a hospital that can repair an aorta, including aortic surgery or a hybrid operating room. Do not choose the closest bed that cannot operate.
Teaching points
- Clues: sudden tearing or ripping chest or back pain, a pulse or blood-pressure difference between the arms, a focal neurologic finding, syncope, Marfan syndrome, or a family history of aortic disease. You will not hear a new aortic-valve leak in the field. Use the story and the exam.
- Aspirin: aspirin is a standard ACS drug. Suspected dissection is a reason to pause. When you are unsure, call medical control.
- Pain control: follow protocol. Do not drop the blood pressure below the floor your protocol sets.
Common errors
- Giving nitro for possible dissection because “chest pain gets nitro.”
- Going to the closest hospital when it cannot operate on the aorta.
- Skipping the 12-lead because you think you already know the diagnosis.
Practice
One-minute check
Partner: sudden tearing back pain, weaker right radial pulse, BP 188/110. Do you give aspirin? Do you give nitro? Where do you go?
Sources & Further Study
Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.
- NASEMSO National Model EMS Clinical Guidelines (2022) — U.S. EMS model language; protocol still wins
- 2025 ACC/AHA ACS Guideline — do not treat every chest pain as ACS by reflex; dissection is a caution for antiplatelet/nitro
- 2022 ACC/AHA Aortic Disease Guideline — rapid recognition and a center that can repair the aorta
Education only. Apply learning within your protocols and medical direction. This is not clinical care guidance.
Check Your Understanding
Questions drawn only from this lesson. After you check, the key is highlighted. Education practice — not a certification exam.