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For further information, see CMDT Part 12-12: Aortic Dissection
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Essentials of Diagnosis
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Sudden searing chest pain with radiation to back, abdomen, or neck in a hypertensive patient
Widened mediastinum on chest radiograph
Pulse discrepancy in the extremities
Acute aortic regurgitation may develop
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General Considerations
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Occurs when a spontaneous intimal tear develops and blood dissects into the media of the aorta
Tear probably results from repetitive torque applied to ascending and proximal descending aorta during the cardiac cycle
Blood entering the intimal tear may extend the dissection into the
Hypertension is important component
Abnormalities of smooth muscle, elastic tissue, or collagen are more common in patients without hypertension
Both absolute pressure levels and the pulse pressure are important in propagation of dissection
Type A dissection
Involves the arch proximal to the left subclavian artery
Death may occur within hours, due to rupture of dissection into pericardial sac or dissection into the coronary arteries, resulting in myocardial infarction
Rupture into plural cavity also possible
Flap of aortic wall created by the dissection may occlude major aortic branches, resulting in ischemia of brain, intestines, kidney, or extremities
Type B dissection typically occurs in the proximal descending thoracic aorta just beyond the left subclavian artery
Conditions associated with increased risk of dissection
Pregnancy
Bicuspid aortic valve
Coarctation
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Sudden onset of severe persistent chest pain
Dissections may occur with minimal pain
Hypertension
Syncope
Hemiplegia
Paralysis of lower extremities
Intestinal ischemia or kidney injury
Peripheral pulses may be diminished or unequal
A diastolic murmur may develop as a result of a dissection in the ascending aorta close to the aortic valve, causing valvular regurgitation, heart failure, and cardiac tamponade
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Differential Diagnosis
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Myocardial infarction
Pulmonary embolism
Arterial embolism
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Diagnostic Procedures
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ECG findings
May be normal in some patients
Left ventricular hypertrophy from long-standing hypertension often present
Acute changes suggesting ...