An aortic dissection is a tear in the inner layer of the aorta that lets blood surge through the tear, causing the inner and middle layers of the wall to separate. If the blood-filled channel ruptures through the outside aortic wall layer, then aortic dissection is often fatal.
What causes an aortic dissection?
The aorta is an artery that runs up through the chest toward the head and then down through the chest, where it divides into a blood vessel that supplies blood to each leg. The walls of the aorta are made up of three layers:
- The innermost layer, the intima, is smooth to allow blood to flow across it
- The middle layer, the media, is made up of muscular and elastic fibers that let the aorta expand and contract with every heartbeat
- The outer layer, the adventitia, includes vessels that supply the aortic wall with oxygen-rich blood
Aortic dissections are divided into two groups:
- Type A: this is the more common and dangerous type involving a tear in the part of the aorta where it exits the heart or a tear in the upper aorta (ascending aorta) which may then extend into the abdomen
- Type B: this involves a tear in the lower aorta only (descending aorta) which may then also extend into the abdomen.
Most of the time, an aortic dissection occurs because of a tear or damage to a weakened area within the inner wall of the aorta. The exact cause is usually hard to pinpoint, but there are a number of risk factors:
- Aging
- Blunt trauma to the chest
- Uncontrolled high blood pressure (hypertension)
- Hardening of the arteries (atherosclerosis)
- Weakened and bulging artery ( pre existing aortic aneurysm)
- Narrowing of the aorta at birth (coarctation)
- Disorders of the connective tissue
- Heart surgery or procedures
- Pregnancy
- High-intensity weightlifting
Symptoms of an aortic dissection
The symptoms of an aortic dissection usually begin suddenly and include severe angina (chest pain). It is often described as a sudden tearing, ripping or shearing sensation that radiates to the neck or down the back. You may experience pain below the chest bone, under the shoulder blades, or in the back, though it may move to your shoulder, neck, arm, jaw, abdomen or hips.
Other symptoms of an aortic dissection include:
- Fainting or dizziness
- Loss of consciousness
- Heavy sweating
- Nausea and vomiting
- Pale or clammy skin
- Shortness of breath
- Heart palpitations
- Anxiety
- Difficulty swallowing
- Abdominal pain
How is an aortic dissection diagnosed?
Detecting an aortic dissection is difficult because the symptoms are similar to those of a variety of health problems. Doctors may suspect an aortic dissection if the following are present:
- Sudden tearing or ripping chest pain
- Widening of the aorta on chest X-ray
- Blood pressure measurement difference between right and left arms
Your doctor may order tests to confirm the diagnosis, including the following:
- Aortic angiography
- Chest X-ray
- Echocardiography
- Computerized tomography (CT) with dye
- Magnetic resonance imaging (MRI)
- Trans esophageal echocardiogram (TEE)
How is an aortic dissection treated?
Treatment for an aortic dissection depends on which part of the aorta is affected and whether other structures in the heart are damaged, such as the aortic valve or the heart arteries.
Surgery is recommended for a dissection in the part of the aorta that ascends from the heart. Dissections in the chest or abdominal sections of the aorta may be managed with surgery and medication.