What are the clinical features of aortic dissection?

Clinical Features of Aortic Dissection

Pain Characteristics

Abrupt-onset severe pain is the hallmark presenting symptom of aortic dissection, occurring in up to 90% of patients, with maximum intensity at the very beginning—distinctly different from myocardial infarction pain which builds gradually. 1, 2

Pain Quality and Onset

• Abrupt onset with maximum intensity at the start occurs in 84% of cases 2
• Severe intensity is reported in 90% of cases 2
• Sharp or stabbing quality in 51-64% of cases, rather than the classic "tearing" or "ripping" description that is often taught 2
• Migrating quality occurs in 12-55% of cases as the dissection extends along the aorta 2

Pain Location by Dissection Type

• Type A dissections (ascending aorta): Chest pain in 80% of cases, more commonly anterior (71%) than posterior (32%) 3
• Type A with extension: Back pain occurs in 47% when dissection extends into the descending aorta 3
• Type B dissections (descending aorta): Back pain in 64% of cases, typically interscapular 3
• Abdominal pain: Occurs in 21% of Type A and 43% of Type B dissections 3

Cardiovascular Manifestations

Hemodynamic Findings

• Pulse deficits occur in less than 20% of current patients (historically 50% in older series), and may be transient due to the intimal flap's changing position 4, 2
• Diastolic murmur indicative of aortic regurgitation is present in approximately 50% of patients 4
• Hypertension is more commonly associated with Type B (distal) aortic dissection 1, 2
• Blood pressure differential between arms or between upper and lower extremities is a significant finding 2

Cardiac Complications

• Congestive heart failure may become the predominant symptom, usually related to severe aortic regurgitation 4, 1
• Cardiac tamponade may result in hypotension and syncope 4, 1

Neurological Manifestations

• Syncope occurs in up to 20% of patients without typical pain or neurological findings, particularly in older patients, those on steroids, and patients with Marfan syndrome 1, 2
• Neurological deficits (loss of consciousness, ischemic paresis) occur in up to 40% of patients with proximal dissection 4, 2
• Stroke or cerebrovascular accident without pain is a potential presentation 2
• Paraplegia may suddenly develop as intercostal arteries are separated from the aortic lumen 4, 2
• Horner's syndrome from compression of the superior cervical sympathetic ganglion 4, 2
• Vocal cord paralysis from compression of the left recurrent laryngeal nerve 4, 2

Visceral and Renal Manifestations

• Oliguria or anuria from renal artery involvement occurs in 8-13% of cases 4, 1
• Persistent abdominal pain with elevation of acute phase proteins and lactate dehydrogenase indicates celiac artery involvement (8% of cases) 4, 2
• Mesenteric artery involvement occurs in 8-13% of cases 4, 2
• Limb ischemia with pulse deficits caused by obliteration of peripheral vessels by involvement of the vessel origin into the dissection 4, 1

Rare and Atypical Presentations

• Painless dissection occurs in up to 6.4% of cases, particularly in older patients, those on steroids, and patients with Marfan syndrome 2, 3
• Hemoptysis or hematemesis from hemorrhage into the tracheobronchial tree or esophageal perforation 4, 2
• Superior vena cava syndrome 4, 2
• Upper airway obstruction from compression 2
• Signs mimicking pulmonary embolism from pulmonary artery compression 4, 2
• Leriche's syndrome (painless pulse loss in both legs) from complete iliac bifurcation obstruction 4, 2
• High fever from release of pyrogenic substances from the aortic wall, which can persist and be misinterpreted as inflammatory disease 4, 2

Typical Patient Profile

The typical patient is a male in his 60s with a history of hypertension presenting with abrupt-onset severe chest or back pain. 1, 2

Critical Clinical Pitfalls

The most catastrophic pitfall is misdiagnosing aortic dissection as myocardial infarction and administering thrombolytic therapy, which can be fatal. 1 Key distinguishing features include:

• Pain in aortic dissection is maximal at onset (84% of cases), whereas MI pain typically builds gradually 2
• Only 80% of Type A dissections present with severe anterior chest pain, and only 60% describe sharp pain 5
• Treating clinicians fail to initially consider aortic dissection in up to 35% of cases 5