Diagnostics

• Order ECG for all patients.

• Order laboratory studies (consider including D-dimer).

• CXR, TTE, and POCUS are considered screening imaging and are usually only obtained as the initial study if:

  • Invasive or risky testing is not desired for low-risk patients.

  • Definitive imaging is not readily available.

  • Patients are too unstable to undergo definitive imaging.

• Definitive imaging includes CTA (gold standard), TEE, and MRA and should be obtained as the:

  • Initial study for high-risk patients

  • Confirmatory study if the diagnosis remains uncertain

Definitive imaging can determine the type of lumen, location, and extent of the dissecting membrane. The identification of a false lumen on imaging is highly suggestive of aortic dissection.

D-dimer, CXR, TTE, and POCUS are not sensitive enough to reliably rule out aortic dissection

Findings are variable and include:

• Normal findings

• Signs of left ventricular hypertrophy

• Nonspecific changes, such as ST depression and T-wave changes

• ST elevation due to coronary artery occlusion

• D-dimer: elevated levels

• Studies to evaluate end-organ damage: e.g., troponin, BMP, lactate

Chest x-ray is often normal.

• Classic radiographic findings of aortic dissection

  • Widened mediastinum (> 8 cm) at the level of the aortic knuckle

  • Alteration of the mediastinal contour seen on serial imaging

  • Mediastinal mass

  • Calcium sign: displacement of the intimal calcification of > 6 mm

• Additional findings: may be present

  • Double aortic contour

  • Pleural cap

  • Pleural effusion

  • Blurring of the aortic knuckle

  • Tracheal shift

  • Widening of the paratracheal stripe

Normal chest x-ray findings do not rule out aortic dissection. If clinical suspicion for acute aortic dissection persists, perform a second imaging study.

• Indications: stable patients, surgical planning

• Suggestive findings

  • Intimal dissection flap

  • Double lumen

  • Aortic dilatation

  • Regions of malperfusion

  • Aortic hematoma

  • Contrast leak: indicates rupture

• Indications: stable patients, contraindications to CTA

• Suggestive findings: similar to CT angiography

• Indications

  • Unstable patients

  • Intraoperative visualization

  • Renal insufficiency or contrast allergy

• Findings may include:

  • Dissection flap (with differential Doppler flow)

  • Double lumen in the ascending aorta

  • Thrombosis in false lumen

  • Evidence of aortic regurgitation

  • Pericardial effusion