What are the clinical signs of aortic dissection?

Clinical Signs of Aortic Dissection

Aortic dissection typically presents with sudden-onset, severe chest or back pain that is maximal at onset and often described as sharp, tearing, ripping, or stabbing in quality, accompanied by hypertension and pulse deficits in up to 20% of cases. 1

Pain Characteristics

• Sudden onset with maximum intensity at beginning (pathognomonic feature)
• Sharp, tearing, ripping, or stabbing quality (reported in 51-64% of cases)
• May have a migrating quality as dissection extends (12-55% of cases)
• Pain may ease or abate, potentially leading to false reassurance

Pain Location by Dissection Type

• Type A (proximal) dissections:

  • Chest pain (80%), more commonly anterior (71%) than posterior (32%)
  • Back pain (47%)
  • Retrosternal chest pain is typical 1

• Type B (distal) dissections:

  • Back pain (64%)
  • Chest pain (63%)
  • Abdominal pain (43%)
  • Interscapular or back pain is typical 1

Cardiovascular Signs

• Pulse deficits in up to 20% of patients (historically found in up to 50% of proximal dissections)
  • May be transient due to changing position of the intimal flap 2, 1
• Diastolic murmur indicative of aortic regurgitation in approximately 50% of patients 2
• Hypertension (typically associated with distal dissections)
• Blood pressure differential between arms
• Signs of cardiac tamponade (hypotension, muffled heart sounds, jugular venous distension)

Neurological Manifestations

• Syncope occurs in up to 20% of cases 2, 1
• Cerebrovascular manifestations (stroke symptoms, focal neurologic deficits)
• Paraplegia due to spinal cord ischemia from involvement of intercostal arteries 2
• Transient global amnesia 3
• Horner's syndrome (due to compression of superior cervical sympathetic ganglion) 2

Other Clinical Signs

• Limb ischemia with pulse deficits due to obstruction of peripheral vessels 2
• Renal involvement leading to oliguria or anuria 2
• Mesenteric ischemia (persistent abdominal pain, elevated acute phase proteins) 2
• Vocal cord paralysis (caused by compression of left recurrent laryngeal nerve) 2
• Hemoptysis or hematemesis (due to hemorrhage into tracheobronchial tree or perforation into esophagus) 2
• Leriche's syndrome (complete obstruction of iliac bifurcation with pulse loss in both legs) 2
• Diffuse alveolar hemorrhage presenting as shortness of breath (rare) 4

Painless Dissection

• Occurs in approximately 6.4% of cases 1
• More common in older patients and those with Marfan syndrome
• Higher likelihood of presenting with:
  • Syncope
  • Stroke
  • Heart failure
  • Sinus tachycardia may be the only sign in some cases 5

Diagnostic Suspicion

• When patients present with both chest and back pain, dissection is suspected in 86% of cases
• Suspicion drops to 45% with chest pain alone and 8% with primarily abdominal pain 1
• High-risk features include:
  • Predisposing conditions (hypertension, Marfan syndrome, bicuspid aortic valve)
  • Characteristic pain features
  • Physical examination findings (pulse deficit, blood pressure differential)

Common Pitfalls

1. Misdiagnosis as other conditions:

   • Acute coronary syndrome
   • Pericarditis
   • Pulmonary embolism
   • Cholecystitis

2. Overlooking painless presentations:

   • Up to 6.4% of dissections may be painless
   • May present primarily with neurological symptoms or syncope 3

3. Delayed diagnosis in atypical presentations:

   • Shortness of breath without chest pain 4
   • Isolated neurological symptoms 3
   • Sinus tachycardia as the only sign 5

4. Administering thrombolytics without ruling out aortic dissection:

   • Could lead to disastrous complications in stroke patients who actually have aortic dissection 3

Remember that an unusual combination of symptoms, especially in patients with risk factors like hypertension, advanced age, or connective tissue disorders, should raise suspicion for aortic dissection. Immediate imaging is crucial as early detection can be lifesaving.