History
Patients with acute aortic dissection typically present with the sudden onset of severe chest pain, although this description is not universal. Some patients present with only mild pain, often mistaken for a symptom of musculoskeletal conditions in the thorax, groin, or back. Consider thoracic aortic dissection in the differential diagnosis of all patients presenting with chest pain.
The location of the pain may indicate where the dissection arises. Anterior chest pain and chest pain that mimics acute myocardial infarction usually are associated with anterior arch or aortic root dissection. This is caused by the dissection interrupting flow to the coronary arteries, resulting in myocardial ischemia. Pain in the neck or jaw indicates that the dissection involves the aortic arch and extends into the great vessels.
Tearing or ripping pain in the intrascapular area may indicate that the dissection involves the descending aorta. The pain typically changes as the dissection evolves.
The pain of aortic dissection is typically distinguished from the pain of acute myocardial infarction by its abrupt onset and maximal severity at onset, though the presentations of the two conditions overlap to some degree and are easily confused. Aortic dissection can be presumed in patients with symptoms and signs suggestive of myocardial infarction but without classic electrocardiographic (ECG) findings.
Aortic dissection is painless in about 10% of patients. [1] Painless dissection is more common in those with neurologic complications from the dissection and those with Marfan syndrome.
Neurologic deficits are a presenting sign in as many as 20% of cases. Syncope is part of the early course of aortic dissection in approximately 5% of patients and may be the result of increased vagal tone, hypovolemia, or dysrhythmia. [1] Cerebrovascular accident (CVA) symptoms include hemianesthesia and hemiparesis or hemiplegia. [1] Altered mental status is also reported. Patients with peripheral nerve ischemia can present with numbness and tingling, pain, or weakness in the extremities.
Horner syndrome is caused by interruption in the cervical sympathetic ganglia and manifests as ptosis, miosis, and anhidrosis. Hoarseness from recurrent laryngeal nerve compression has also been described.
Cardiovascular manifestations involve symptoms suggestive of congestive heart failure [1] secondary to acute severe aortic regurgitation. These include dyspnea and orthopnea.
Respiratory symptoms can include dyspnea and hemoptysis if dissection ruptures into the pleura or if tracheal or bronchial obstruction has occurred. Physical findings of a hemothorax may be found if the dissection ruptures into the pleura.
Other manifestations include the following [17] :
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Dysphagia from compression of the esophagus
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Flank pain if the renal artery is involved
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Abdominal pain if the dissection involves the abdominal aorta
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Fever
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Anxiety and premonitions of death
A retrospective chart review of 83 patients with a thoracic aortic dissection revealed that only 40% of alert patients were asked the basic questions about their pain. Remember to cover the P, Q, R, S, and T (position, quality, radiation, severity, and timing) of pain in all able patients. Timing includes the rate of onset, duration, and frequency of episodes. Also ask about migration of pain, aggravating or alleviating factors, and associated symptoms.
Physical Examination
Hypertension may result from a catecholamine surge or underlying essential hypertension. [1, 18] Hypotension is an ominous finding and may be the result of excessive vagal tone, cardiac tamponade, or hypovolemia from rupture of the dissection.
An interarm blood pressure differential greater than 20 mm Hg should increase the suspicion of aortic dissection, but it does not rule it in. Significant interarm blood pressure differentials may be found in 20% of people without aortic dissection.
Signs of aortic regurgitation include bounding pulses, wide pulse pressure, and diastolic murmurs. Acute, severe aortic regurgitation may result in signs suggestive of congestive heart failure [1] : dyspnea, orthopnea, bibasilar crackles, or elevated jugular venous pressure.
Other cardiovascular manifestations include findings suggestive of cardiac tamponade (eg, muffled heart sounds, hypotension, pulsus paradoxus, jugular venous distention, Kussmaul sign). Tamponade must be recognized promptly. Superior vena cava syndrome can result from compression of the superior vena cava from a large, distorted aorta. Wide pulse pressure and pulse deficit or asymmetry of peripheral pulses are reported.
Patients with right coronary artery ostial dissection may present with acute myocardial infarction, commonly inferior myocardial infarction. Pericardial friction rub may occur secondary to pericarditis.
Neurologic deficits are a presenting sign in up to 20% of cases. The most common neurologic findings are syncope and altered mental status. Syncope is part of the early course of aortic dissection in about 5% of patients and may be the result of increased vagal tone, hypovolemia, or dysrhythmia. Other causes of syncope or altered mental status include strokes from compromised blood flow to the brain or spinal cord and ischemia from interruption of blood flow to the spinal arteries.
Peripheral nerve ischemia can manifest as numbness and tingling in the extremities. Hoarseness from recurrent laryngeal nerve compression also has been described. Horner syndrome is caused by interruption in the cervical sympathetic ganglia and presents with ptosis, miosis, and anhidrosis.
Other diagnostic clues include a new diastolic murmur or asymmetrical pulses. Pay careful attention to carotid, brachial, and femoral pulses on initial examination and look for progression of bruits or development of bruits on reexamination. Physical findings of a hemothorax may be found if the dissection ruptures into the pleura.
Complications
Complications are diverse and numerous; anatomic-related complications are deducible and include the following:
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Hypotension and shock as a result of aortic rupture, with eventual death from exsanguination
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Pericardial tamponade secondary to hemopericardium; this complicates type A aortic dissection
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Acute aortic regurgitation as a complication of proximal aortic dissection propagating into a sinus of Valsalva with resultant aortic valve insufficiency
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Pulmonary edema secondary to acute aortic valve regurgitation
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Rare occurrence of right or left coronary ostium involvement leading to myocardial ischemia
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Neurologic findings due to carotid artery obstruction - Ischemic CVA, hemiplegia, hemianesthesia (aortic branch involvement can lead to spinal cord ischemia, ischemic paraparesis, and paraplegia)
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Mesenteric and renal ischemia - Can lead to bowel or visceral ischemia, renal infarction, hematuria, or acute renal failure (ARF)
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Compressive symptoms, such as superior vena cava syndrome, Horner syndrome (when it affects the superior cervical ganglia), dysphagia (when it involves the esophagus), airway compromise, and hemoptysis (when it compresses the bronchus)
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Other compressive symptoms - Can be associated with vocal cord paralysis and hoarseness
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Claudication - Can develop from extension of the dissection into the iliac arteries
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Redissection and progressive aortic diameter enlargement
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Aneurysmal dilatation and saccular aneurysm
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Aortic dissection. CT scan showing a flap (right side of image).
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Aortic dissection. True lumen versus false lumen in an intimal flap.
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Aortic dissection. Left subsegmental atelectasis and left pleural effusion. Flap at lower right of image.
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Aortic dissection. Significant left pleural effusion.
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Aortic dissection. CT scan showing a flap (center of image).
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Aortic dissection. CT scan showing a flap (center of image).
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Aortic dissection. CT scan showing a flap.
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Aortic dissection. CT scan showing a flap.
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Aortic dissection. Mediastinal widening.
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Aortic dissection. CT scan showing a flap.
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Aortic dissection. CT scan showing a flap.
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Aortic dissection. CT scan showing a flap.
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Aortic dissection. Thrombus and a patent lumen.
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Aortic dissection. Thrombus.
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Aortic dissection. True lumen and false lumen separated by an intimal flap.
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Aortic dissection. Mediastinal widening.
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Aortic dissection. CT scan showing a flap.
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Aortic dissection. Intimal flap and left pleural effusion.
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Image A represents a Stanford A or a DeBakey type 1 dissection. Image B represents a Stanford A or DeBakey type II dissection. Image C represents a Stanford type B or a DeBakey type III dissection. Image D is classified in a manner similar to A but contains an additional entry tear in the descending thoracic aorta. Note that a primary arch dissection does not fit neatly into either classification.
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Aortic dissection.
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Chest radiograph of a patient with aortic dissection. Image courtesy of Dr. K. London, University of California at Davis Medical Center.
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Chest radiograph of a patient with aortic dissection presenting with hemothorax.
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Chest radiograph demonstrating widened mediastinum in a patient with aortic dissection.
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Angiogram demonstrating dissection of the aorta in a patient with aortic dissection presenting with hemothorax.
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Electrocardiogram of a patient presenting to the ED with chest pain; this patient was diagnosed with aortic dissection.
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Patient with an ascending type A aortic dissection showing the intimal flap. Image courtesy of Kaiser-Permanente.
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Patient with an ascending type A aortic dissection showing the intimal flap. Image courtesy of Kaiser-Permanente.
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Patient with an ascending type A aortic dissection showing the intimal flap. Image courtesy of Kaiser-Permanente.
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Patient with an ascending type A aortic dissection showing the intimal flap. Image courtesy of Kaiser-Permanente.
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Patient with a type A aortic dissection involving the ascending and descending aorta. Image courtesy of Kaiser-Permanente.
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Patient with a type A aortic dissection involving the ascending and descending aorta. Image courtesy of Kaiser-Permanente.
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Patient with a type A aortic dissection involving the ascending and descending aorta. Image courtesy of Kaiser-Permanente.
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Patient with a type A aortic dissection involving the ascending and descending aorta. Image courtesy of Kaiser-Permanente.
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Patient showing a type B aortic dissection with extravasation of blood into the pleural cavity. Image courtesy of Kaiser-Permanente.
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Patient showing a type B aortic dissection with extravasation of blood into the pleural cavity. Image courtesy of Kaiser-Permanente.
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Patient showing a type B aortic dissection with extravasation of blood into the pleural cavity. Image courtesy of Kaiser-Permanente.
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Patient showing a type B aortic dissection with extravasation of blood into the pleural cavity. Image courtesy of Kaiser-Permanente.
