Nontraumatic thoracic aortic dissection

(Redirected from Aortic dissection)

Not to be confused with traumatic aortic transection

Background

Aortic segments
Branches of the aorta
Aortic anatomy. The aorta is divided into 5 anatomical segments– aortic root, ascending aorta, aortic arch, descending thoracic aorta, and abdominal aorta. Its wall is composed of three layers – intima, media, and adventitia.
  • Most commonly seen in men 60-80 yrs old
  • Intimal tear with blood leaking into media
  • Mortality in first 48 hours of acute presentation is high
    • Commonly quoted as 1-2% per hour, but this is based on a series from the 1950s[1]
    • More recent data suggests mortality for type A dissection is 0.5% per hour when treated medically, and 0.1% per hour when managed surgically[2]
  • Diagnosis delayed > 24hr in 50% of cases
  • Bimodal age distribution

Clinical Features

General

  • Symptoms
    • Tearing/ripping pain (10.8x increased disease probability)
      • 64% described the pain as sharp vs 50.6% who described it as tearing or ripping[3]
    • Migrating pain (7.6x)
    • Sudden chest pain (2.6x)
    • History of hypertension (1.5x)
  • Signs

Specific

Differential Diagnosis

Chest pain

Critical

Emergent

Nonemergent

Hypertension

Evaluation

Dissection of the aortic arch: initial CXR normal visualization of the calcification shadow in the aortic arch (left); CXR 4 months later with calcification shifted centrally into the shadow of the aortic arch with a blurred external border (middle); CT scan coronal (top right) and axial (lower right).
CXR showing widened mediastinum and porminent aortic knob
Type A dissection with pericardial effusion as a result. Red arrows showing ascending and descending thoracic aorta. The blue arrows pericardial effusion.
CT chest with contrast of thoracic aortic dissection.

Aortic Dissection Detection Risk Score (ADD-RS)

A score 1 should be awarded for each of the 3 categories that contain at least one of the listed features

Predisposing conditions Pain features Physical findings

Chest, back, or abdominal pain described as:

  • Abrupt in onset/severe in intensity

AND

  • Ripping/tearing/sharp or stabbing quality
  • Evidence of perfusion deficit
    • Pulse deficit
    • Systolic BP differential
    • Focal neurological deficit (in conjunction with pain)
  • Murmur of aortic insufficiency (new or not known to be old and in conjunction with pain)
  • Hypotension of shock state
Score Category Prevalence
0 Low 6%
1 Intermediate 27%
>1 High 39%

No Risk Factor Screening

  • CXR
    • Abnormal in 90% (3.4x)
    • Mediastinal widening (seen in 56-63%)
    • Left sided pleural effusion (seen in 19%)
    • Widening of aortic contour (seen in 48%), displaced calcification (6mm), Calcium sign (look for white line of calcium within aortic knob and measure to outer edge of the aortic knob - distance greater than 0.5 cm is positive and > 1 cm is highly suspicious for dissection), aortic kinking, double density sign


Low-Intermediate

(Based on ADD-RS)[6][7][8]

  • D-dimer for ADD-RS ≤ 1 (low or intermediate risk)

High Risk/Definitive

  • CT aortogram chest
    • Study of choice
    • Similar sensitivity/specificity to TEE and MRA
  • TEE
    • If CT delayed due to contrast allergy or availability, or patient instability.
    • TEE has a sensitivity of 98% and 95% specific[9]

Other Findings

Type A Aortic Dissection[10]
Abdominal Aortic Dissection on Ultrasound
  • ECG
    • LVH on admission ECG (3.2x)
    • Ischemia (esp inferior) - 15%
    • Nonspec ST-T changes - 40%
  • Bedside US
    • Can help in ruling in patients when AOFT is >4cm
    • Rule out pericardial effusion and tamponade, especially in hypotension, syncope, dyspnea

Aortic Dissection Classification

  • Stanford
    • Type A: Involves any portion of ascending aorta
    • Type B: Isolated to descending aorta
  • De Bakey
    • Type I: Involves the ascending and descending aorta
    • Type II: Involves only the ascending aorta
    • Type III: Involves only the descending aorta
Classification of aortic dissection
Image AoDissect DeBakey1.png AoDissect DeBakey2.png AoDissect DeBakey3.png
Percentage 60% 10–15% 25–30%
Type DeBakey I DeBakey II DeBakey III
Classification Stanford A (Proximal) Stanford B (Distal)

Management

General Principles

  • Control pain to reduce sympathetic stimulation.
    • Fentanyl is easily titratable with minimal cardiovascular effects
  • Right radial arterial line or right arm blood pressure will generally be the most accurate
  • Reducing heart rate while maintaining low-normal blood pressure reduces aortic flow acceleration, thereby reducing shear force on the intimal wall
    • Goal: HR < 60 bpm, SBP 100-120 mmHg
    • Control heart rate before blood pressure[11]
    • Beta blockers are good first-line option, since they reduce heart rate and aortic wall tension
      • Use β-blockers with caution in severe, acute aortic regurgitation - may worsen shock if dependent on compensatory tachycardia

Heart Rate control

  1. Esmolol
    • Advantage of short half life, easily titratable
    • Bolus 0.5mg/kg over 1min; infuse 0.05mg/kg/min (titrate upward in 0.05mg/kg/min increments to a maximum of 0.3 mg/kg/min)
    • Esmolol Drip Sheet
  2. Labetalol - has both α and beta effects
    • Push dose - 10-20mg with repeat doses of 20-40mg q10min up to 300mg
    • Drip - Load 15-20mg IV, followed by 5mg/hr
  3. Metoprolol
    • 5mg IV x 3; infuse at 2-5mg/hr
  4. Diltiazem - Use if contraindications to beta-blockers
    • Loading 0.25mg/kg over 2–5 min, followed by a drip of 5mg/h

Blood pressure control (vasodilators)

Use if needed after beta-blockade.

  1. Nicardipine:
    • 5mg/hr start, then titrate up by 2.5mg/hr every 10 min until goal
    • Once at goal, drop to 3mg/hr and re-titrate from there
    • May initially bolus 2mg IV[12]
  2. Clevidipine
    • 1-2 mg/hr
    • Double dose every 90 seconds until approaching goal BP, then increase in smaller amounts every 5-10 minutes until goal achieved.[13]
  3. Nitroprusside 0.3-0.5mcg/kg/min - Risk of cerebral blood vessel vasodilation and CN/Thiocynate toxicity
  4. Fenoldopam
  5. Enalapril

Surgery

  • Type A (any portion of ascending aorta)
    • Requires surgery
  • Type B (isolated to descending aorta)
    • Primarily medical management with surgery consultation

Disposition

  • Admission to OR or ICU

Complications

  • AV Regurgitation/Insufficiency
    • CHF with diastolic murmur
  • Rupture
  • Vascular obstruction
    • Coronary: ACS
    • Carotid: CVA
    • Lumbar: Paraplegia

See Also

External Links

References

  1. ↑ Hirst AE Jr, et al. Dissecting aneurysm of the aorta: a review of 505 cases. Medicine (Baltimore). 1958;37(3):217-279.
  2. ↑ Harris, KM. et al. Early mortality in type A acute aortic dissection: Insights from the International Registry of Acute Aortic Dissection. JAMA Cardiol. 2022;7(10):1009-1015.
  3. ↑ Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA. 2000;283(7):897–903.
  4. ↑ 4.0 4.1 4.2 Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA. 2000; 283(7):897-903.
  5. ↑ Spittell PC, S et al. Clinical features and differential diagnosis of aortic dissection: experience with 236 cases (1980 through 1990) Mayo Clin Proc. 1993;68:642–51.
  6. ↑ Circulation. 2018 Jan 16;137(3):250-258. doi: 10.1161/CIRCULATIONAHA.117.029457. Epub 2017 Oct 13. Nazerian, et al. Diagnostic Accuracy of the Aortic Dissection Detection Risk Score Plus D-Dimer for Acute Aortic Syndromes: The ADvISED Prospective Multicenter Study.
  7. ↑ Asha SE et al. "A systematic review and meta-analysis of D-dimer as a rule out test for suspected acute aortic dissection." Annals of EM. 66;4;368-377Ocotber 2015.
  8. ↑ Shimony A, et al. Meta-analysis of usefulness of d-dimer to diagnose acute aortic dissection. Am J Cardiol. 2011; 107(8):1227-1234.
  9. ↑ Shiga T, Wajima Z, Apfel CC, Inoue T, Ohe Y. Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis. Arch Intern Med. 2006 Jul 10;166(13):1350-6.
  10. ↑ http://www.thepocusatlas.com/echocardiography-1
  11. ↑ Tsai TT, Nienaber CA, and Eagle KA. Acute Aortic Syndromes. Circulation. 2005;112:3802–3813
  12. ↑ Curran MP et al. Intravenous Nicardipine. Drugs 2006; 66(13): 1755-1782. http://emcrit.org/wp-content/uploads/2014/07/bolus-dose-nicardipine.pdf
  13. ↑ UpToDate Inc. Clevidipine [Drug information]. In:UpToDate Lexidrug. Wolters Kluwer; 2025. Accessed August 1, 2025.
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