Clinical Symptoms and Signs of Aortic Dissection
The hallmark presentation of aortic dissection is sudden-onset, severe chest pain that is maximal at onset and often described as sharp, tearing, ripping, or stabbing in quality. 1
Primary Clinical Features
Pain Characteristics
- Location:
- Proximal dissections (Type A): Retrosternal chest pain
- Distal dissections (Type B): Interscapular or back pain
- Quality: Sharp, tearing, ripping, or stabbing (unlike the gradually increasing, dull pain of myocardial infarction)
- Onset: Abrupt with maximum intensity at the beginning
- Migration: Pain may change location as the dissection progresses
Vital Signs and Hemodynamic Findings
- Blood pressure:
- Hypertension: Typically associated with distal aortic dissection
- Hypotension: May indicate complications such as cardiac tamponade or rupture
- Pulse deficits: Present in up to 20% of patients with acute aortic dissection, but historically found in up to 50% of patients with proximal dissections 1
- These may be transient due to the changing position of the intimal flap
Cardiovascular Signs
- Diastolic murmur of aortic regurgitation (present in approximately 50% of patients)
- Signs of cardiac tamponade (muffled heart sounds, jugular venous distention, hypotension)
- Congestive heart failure symptoms due to severe aortic regurgitation
Less Common Presentations
Neurological Manifestations (up to 40% of proximal dissections)
- Syncope (present in up to 20% of patients, sometimes without pain) 1
- Stroke-like symptoms
- Loss of consciousness
- Ischemic paresis
- Paraplegia (due to spinal cord ischemia from involvement of intercostal arteries)
Vascular Complications
- Limb ischemia with pulse deficits
- Leriche's syndrome (pulse loss in both legs, typically painless)
- Renal involvement leading to oliguria or anuria
- Mesenteric ischemia (persistent abdominal pain, elevated acute phase proteins, increased lactate dehydrogenase)
Rare Manifestations
- Vocal cord paralysis (compression of left recurrent laryngeal nerve)
- Hemoptysis or hematemesis (hemorrhage into tracheobronchial tree or esophageal perforation)
- Superior vena cava syndrome
- Upper airway obstruction
- Horner's syndrome
- Signs mimicking pulmonary embolism
- High fever (due to release of pyrogenic substances from the aortic wall)
Atypical Presentations
It's crucial to recognize that aortic dissection can present atypically:
- Altered mental status 2
- Low back pain as the only complaint 2
- Asymptomatic presentations (rare, usually incidental findings) 3
- Association with other acute conditions like tension pneumothorax 4
Risk Factors to Consider
When evaluating patients with suspicious symptoms, consider these risk factors:
- Advanced age
- Male gender
- Hypertension (most common risk factor)
- Existing aortic aneurysm
- Genetic connective tissue disorders (Marfan, Loeys-Dietz, Ehlers-Danlos syndromes)
- Bicuspid aortic valve 5
- History of cardiac catheterization 3
Clinical Pitfalls to Avoid
Misdiagnosis as acute coronary syndrome: The pain of aortic dissection is maximal at onset, while MI pain typically builds gradually.
Overlooking painless presentations: Up to 20% of patients may present with syncope or other symptoms without the classic pain.
Failure to recognize neurological symptoms as manifestations of dissection: Stroke-like symptoms may be the primary presentation.
Attributing fever to infectious causes: Fever can occur in aortic dissection due to inflammatory processes.
Delaying diagnosis in patients with atypical symptoms: Consider aortic dissection in any patient with risk factors and unexplained symptoms.
Remember that prompt diagnosis is critical, as mortality increases by 1-2% per hour in untreated patients with acute aortic dissection 5.