What are the clinical presentation and management of aortic dissection?

Clinical Presentation and Management of Aortic Dissection

The clinical presentation of aortic dissection is characterized primarily by sudden, severe chest or back pain that is often described as sharp, tearing, or ripping in nature, with maximum intensity at onset, occurring in up to 90% of patients. 1

Clinical Presentation

Typical Presentation

• Pain is the most common presenting symptom, with abrupt onset and maximum intensity at the beginning, unlike myocardial infarction pain which typically builds gradually 1
• Pain location varies by dissection type: retrosternal pain in proximal (Type A) dissections and interscapular/back pain in distal (Type B) dissections 1
• The typical patient is a male in his 60s with a history of hypertension 1
• Hypertension is more commonly associated with distal aortic dissection 1

Atypical Presentations

• Up to 20% of patients may present with syncope without typical pain or neurological findings 1
• Cardiac failure may become the predominant symptom, usually related to severe aortic regurgitation 1
• Neurological manifestations including stroke, altered mental status, or paraplegia may occur due to vessel obstruction 1, 2
• Pulse deficits or limb ischemia may result from obliteration of peripheral vessels 1
• Cardiac tamponade may cause hypotension and syncope 1
• Oliguria or anuria may occur with renal artery involvement 1

Physical Examination Findings

• Pulse deficits are found in less than 20% of patients with acute aortic dissection 1
• Diastolic murmur indicative of aortic regurgitation is present in about half of patients 1
• Neurological deficits occur in up to 40% of patients with proximal aortic dissection 1, 3

Diagnostic Approach

Initial Assessment

• Establish intravenous access, obtain blood samples, perform ECG, and initiate continuous heart rate and blood pressure monitoring 3
• Chest X-ray should be performed in all stable patients (abnormal in 60-90% of cases) but omitted in unstable patients to avoid treatment delays 3
• Every patient with suspected aortic dissection should undergo urgent definitive imaging 1, 3

Imaging Modalities

• Transesophageal echocardiogram (TEE), computed tomographic imaging (CT), or magnetic resonance imaging (MRI) are all appropriate for diagnosis 1, 3
• Modern multidetector CT is fast, widely available, and has high sensitivity and specificity 4
• Selection of specific imaging modality should be based on patient variables and institutional capabilities 3

Management

Immediate Management

• Reduce systolic blood pressure to 100-120 mmHg using IV beta-blockers as first-line therapy 3
• Target heart rate of 60 beats per minute or less 3
• For severe hypertension despite beta-blockade, add sodium nitroprusside 3
• Provide pain relief with morphine sulfate 3
• Transfer to intensive care unit for appropriate monitoring 3

Type-Specific Management

• Type A dissection (involving ascending aorta): Urgent surgical consultation and evaluation for emergent surgical repair 3
• Type B dissection (involving descending aorta): Initially manage medically unless life-threatening complications develop 3
• Surgical options for Type A include implantation of a composite graft in the ascending aorta 3
• For complicated Type B dissection, emergency intervention (preferably TEVAR - Thoracic Endovascular Aortic Repair) is recommended 3

Prognosis and Complications

• Left untreated, about 75% of patients with dissections involving the ascending aorta die within 2 weeks 5
• With successful initial therapy, the 5-year survival rate increases to 75% 5
• Complications include aortic rupture, pericardial tamponade, aortic regurgitation, malperfusion syndrome, and aneurysm formation 3, 4

Special Considerations

• Patients with genetic connective tissue disorders (Marfan, Loeys Dietz, Ehlers Danlos syndrome) and bicuspid aortic valves are at increased risk at a younger age 6
• In patients with hereditary diseases, lifelong beta-adrenergic blockade is recommended for prevention of dissection 3
• For pregnant patients, management requires a multidisciplinary team at specialized centers 3

Common Pitfalls and Caveats

• Aortic dissection can mimic other conditions such as acute coronary syndrome, pulmonary embolism, or stroke 1, 2
• Atypical presentations without chest pain can lead to delayed diagnosis 2
• Thrombolytic therapy can be catastrophic if administered to a patient with aortic dissection misdiagnosed as myocardial infarction 1
• Elevated D-dimer may be a helpful laboratory marker but should not be used to rule out dissection 1, 6