Aortic dissection involves bleeding into and along the wall of the aorta (the major artery from the heart), most often because of a tear or damage to the inner wall of the artery. This usually occurs in the thoracic (chest) portion of the aorta, but may also occur in the abdominal portion.

The exact cause is unknown, but risks include atherosclerosis (hardening of the arteries) and hypertension (high blood pressure). Traumatic injury is a major cause of aortic dissection, especially blunt trauma to the chest as can be caused by hitting the steering wheel of a car during an accident.

Aortic dissection may also be associated with other injury, infection, congenital (present from birth) weakness of the aorta, collagen disorders (such as Marfan's syndrome, pseudoxanthoma elasticum, Ehlers-Danlos syndrome, relapsing polychondritis, or abdominal aortic aneurysm). Pregnancy, valve disorders (including aortic insufficiency), and coarctation of the aorta may also be associated with aortic dissection.

Aortic dissection occurs in approximately 2 out of every 10,000 people. It can affect anyone but is most often seen in men aged 40 to 70.

• chest pain
  • sudden, severe, sharp, stabbing, tearing, or ripping
  • located below the sternum, then radiates under the shoulder blades or to the back
  • may radiate to shoulder, neck, arm, jaw, abdomen, or hips
  • location may change -- pain typically moves distally (to arms and legs) as the aortic dissection progresses in the same direction
• changes in thought ability, concentration (confusion, disorientation)
• decreased movement, any location
• decreased sensation, any location
• intense anxiety, anguish
• pallor
• rapid pulse (heart rate)
• profuse sweating
• dry skin/mouth, thirst
• nausea, vomiting
• dizziness, fainting
• shortness of breath (dyspnea)
  • difficulty breathing when lying flat (orthopnea)

Note: Symptoms usually begin suddenly.

Additional symptoms that may be associated with this disease:

• excessive yawning
• clammy skin
• weak or absent pulse
• cough
• high blood pressure

Listening with a stethoscope (auscultation) at the chest and abdomen may reveal a "blowing" murmur over the aorta, a heart murmur, or other abnormality. There may be decreased (weak) pulses in the arms and hands.

There may be low blood pressure, bulging neck veins, or signs resembling a heart attack. There may be signs of shock (inadequate blood flow to the body tissues), but with normal blood pressure.

Aortic dissection or aortic aneurysm may be revealed on:

• Echocardiogram -- ultrasound examination of the heart
• Transesophageal echocardiogram (TEE)
• Chest X-ray -- may show mediastinal (chest) widening or pleural effusion (fluid in the lining of the lung)
• Chest MRI or CT scan of chest with dye
• Aortic angiography
• Doppler ultrasonography (occasionally performed)
• ECG -- may show signs of left ventricular hypertrophy (enlargement), secondary to chronic high blood pressure
• Hematocrit (a measurement of red blood cells) -- performed to evaluate blood loss

The goal of treatment is prevention of complications. Hospitalization is required.

Antihypertensives (drugs that lower blood pressure) may be prescribed, and these may be given through a vein (intravenous). Potent analgesics (pain relievers) are usually needed for pain. Cardiac medications, such as beta-blockers, may reduce some of the symptoms.

Surgical repair or replacement of the section of aorta is curative in some cases. If the aortic valve is compromised by the dissection, aortic valve replacement is necessary. If the coronary (heart) arteries are involved, a coronary bypass is also performed.

• bleeding from the aorta
• aortic rupture causing rapid blood loss, shock
• clot formation
• insufficient circulation past the area of the dissection
• irreversible kidney failure
• stroke
• heart attack
• cardiac tamponade -- a condition where fluid acccumulates in the lining of the heart, which impairs the heart's ability to pump out blood

Adequate treatment and control of atherosclerosis (hardening of the arteries) and hypertension (high blood pressure) may reduce risk. Use safety precautions to reduce the risk of injury. Many cases are not preventable.