Aortic regurgitation: Acute aortic regurgitation can result from dilation of the aortic root. This may cause acute left heart failure with hypotension and pulmonary edema. Respiratory failure can ensue and again, surgical repair/replacement is required urgently.

Inferior myocardial infarction: When the ascending aortic dissection involves the ostium of the right coronary artery, an inferior myocardial infarction can occur. This is diagnosed on the 12-lead ECG where ST elevation is seen in leads II, III and aVF with reciprocal ST depression in the high lateral leads I and aVL. Treatment is emergent coronary bypass surgery. Review STEMI here.

Carotid artery dissection: When the carotid artery is involved in the ascending aortic dissection, symptoms of carotid artery dissection may occur which include headache, neck pain and Horner’s syndrome (ptosis - drooping eyelid, miosis - constriction of the pupil, and hemianhidrosis - lack of sweating on one side of the face), tinnitus and focal neurologic deficits.

Cardiac tamponade: An acute pericardial effusion can occur causing cardiac tamponade if the proximal portion of the ascending aortic dissection ruptures into the pericardium. In this situation physical exam findings include:

- Sinus tachycardia
- Elevated jugular venous pressure
- Pulsus paradoxus (see below)
- Pericardial friction rub (from pericarditis if present)
- Distant heart sounds (from heart sound muffling related to the pericardial effusion)
- Kussmaul’s sign (rarely) - increase in jugular venous pressure during inspiration

"Pulsus paradoxus" which is present in cardiac tamponade reflects a decrease in systolic blood pressure with inspiration of more than 12 mm Hg. Pulsus paradoxus also occurs in severe asthma or COPD exacerbations.

Aortic Rupture: If the aorta ruptures, blood will rapidly accumulate in the thoracic cavity resulting in profound hypotension and death.