Please refer to this section for definitions of common terms used in discussing aortic dissections:

Aneurysm: a bulge or “ballooning” in the wall of an artery. Often caused by weakening in the walls of the artery. Aneurysms are associated with catastrophic complications such as a rupture of the aneurysm or dissection.

Aorta: main vessel that sends blood away from the heart to the rest of the body

Aortic valve: the aortic valve allows blood to flow form the heart's left ventricle into the aorta. It normally has 3 cusps.

Aortic insufficiency: also known as aortic regurgitation. A leakage of the aortic valve allows blood to flow back into the heart when it is pumping blood to the body.

Aortography: Before the use of CT scans and TEEs, contrast dye was injected directly into the aorta as a means to diagnose aortic dissections. Aortography is an invasive test, and therefore has been generally replaced by non-invasive tests.

Arterial line: a catheter placed into an artery. Allows physicians to measure blood pressure in real time, as well as draw blood samples.

Beta blocker: a medication used to treat high blood pressure, congestive heart failure, abnormal heart rhythms, and chest pain. It prevents adrenaline from acting on the body, which results in a decrease in heart rate and blood pressure.

Bicuspid aortic valve: in about 1-2% of the general population, the aortic valve has only 2 cusps instead of the normal 3. It usually does not cause any symptoms, but has been associated with several heart problems.

Cardiac catheterization: a procedure in which a catheter, a thin flexible tube, is passed into the right or left side of the heart. This procedure can be used to obtain information about the heart and its blood vessels, or can be used to provide treatment for heart conditions such as to remove a blockage during a heart attack.

Cardioplegic solution: a solution used during surgery to paralyze the heart. Allows surgeons to operate on the heart with relative safety, as it maintains heart muscle despite lack of blood flow to the heart.

Cardiopulmonary bypass: a procedure in which a machine takes over the function of the heart and lungs. Used during surgery to maintain blood circulation and oxygenation to the body while surgeons operate on the heart and lungs.

Connective Tissue Disorders: Connective tissue refers to the parts in the human body that gives tissues (such as tendons, ligaments, and cartilage) shape, structure, and support. Connective tissue disorders are a group of disorders that affect connective tissue. Each disorder has a different set of symptoms and treatment, but several are associated with an increased frequency of aortic dissections.

Coumadin: also known as warfarin. A medication that inhibits the formation of clotting factors that depend on Vitamin K. This decreases the body's ability to form clots, which helps prevent the body from developing dangerous blood clots (for example, if an artificial substance is placed in the body). However, this also places patients at an increased risk of excessive bleeding. Patients on coumadin must have their blood checked regularly to ensure they are on an appropriate dose of coumadin, and must be have a steady, regular intake of vitamin K (usually obtained from green, leafy vegetables).

Creatine kinase: an enzyme that may be measured in the blood. A type of CK, CK-MB, is released in significant quantities when the heart suffers damage.

CT scan: Computed Tomography scan. A series of x-rays are taken and compiled by a computer. CT scans show much more detail than single x-rays can provide. For aortic dissections, a dye is injected into the patient's arteries. This allows physicians to have more detailed pictures of a patient's blood vessels.

Dacron: a manmade material that can be used in the body to replace some body tissues. It is well tolerated by the body and causes very few reactions.

Defibrillator: device that can deliver a therapeutic electric shock to the heart. Defibrillators are often used to restart the heart if it is in a dangerous arrhythmia such as ventricular fibrillation.

Echocardiogram: a non-invasive test in which ultrasound waves, similar to those used for pregnant women, are used to view the heart or nearby structures. Echocardiograms can be taken through the chest, known as a transthoracic echocardiogram (TTE), or through the esophagus, known as a transesophageal echocardiogram (TEE). TTEs do not cause any patient discomfort, however because a TEE goes through the patient's esophagus, patients are slightly sedated so that they do not experience any discomfort. No radiation is involved in this test.

Ehlers-Danlos syndrome: genetic disorder that results in a defect in collagen synthesis. The severity may range from mild to life-threatening. Common symptoms include extremely flexible joints, eye lens dislocation, and bone deformities. Joints have a high tendency to dislocate.

EKG: a non-invasive test in which the electrical signals generated by the heart are recorded. EKGs are often used to help diagnose heart problems, such as heart attacks.

Giant cell arteritis: vasculitis of large and medium sized vessels. May be associated with a headache, and may lead to blindness.

Great vessel injury: physicians may refer to a “great vessel” injury. This refers to large vessels such as the aorta, vena cava (large vessels that return blood to the heart), and pulmonary arteries and veins (blood vessels that carry blood to and from the lungs). Great vessel injuries may often occur during penetrating trauma or after sudden decelerations such as a car accident.

Hypertension: Also known as high blood pressure. Blood pressure refers to the pressure measured as blood is pumped through the blood vessels. Normal blood pressure is around 120 systolic (peak pressure in the arteries) over 80 diastolic (lowest pressure in the arteries). Hypertension is diagnosed when blood pressure is above 140 systolic or 90 diastolic on 2 separate occasions.

Inflammation: a process by which the body's white blood cells protect us against disease and infection.

Inflammatory disease: in some diseases, the body's immune system triggers inappropriately against its own tissues. The body is attacking normal tissues as if they are infected or abnormal.

Intravenous line (IV): a catheter placed into a vein. Allows physicians to administer fluids and medications, as well as draw blood samples.

Marfan Syndrome: a connective tissue disorder caused by a defect in a gene called fibrillin-1. This disorder is associated with an increased frequency of aortic dissections. Patients with Marfan syndrome are often very tall and thin, may have slender, tapering fingers, and eye problems. However, patients may have very mild cases without symptoms.

MRI: Magnetic resonance imaging. An extremely accurate non-invasive test that may be used to evaluate the aorta. MRI uses magnetic waves to produce images. However, it requires patients remain still for more than 30 minutes and is not readily available in emergent situations

Murmur: an extra or unusual sound made by blood moving in the heart. Some are insignificant, but some may signify to a physician that further investigation is required.

Myocardial infarction: a heart attack. This occurs when the heart's muscles are not receiving enough oxygen, such as when the coronary arteries, the arteries supply blood to the heart, are blocked.

Pancreatitis: inflammation of the pancreas. Usually associated with gallstones and excessive alcohol use.

Pericarditis: inflammation in the pericardium, the sac surrounding the heart.

Pulmonary embolism: blood clot that lodges in the arteries that provide blood to the lungs. This can be a life-threatening disease and is usually characterized by sudden shortness of breath and chest pain. Pulmonary embolisms are often associated with deep vein thrombosis (DVT), blood clot in the veins of the leg often caused by long periods of immobility.

Rheumatoid arthritis: systemic disease in which the body's own immune system causes chronic inflammation of the tissue around the joints. Affects other organs in the body as well.

Syphilitic aortitis: if untreated, the sexually transmitted disease syphilis may affect and damage the aorta.

Takayasu arteritis: a vasculitis that primarily affects the aorta and its main branches.

Turner Syndrome: a genetic chromosomal abnormality in which a person has only one X chromosome instead of two sex-determining (X or Y) chromosomes. While associated with many other symptoms, patients with Turner syndrome are predisposed to cardiovascular problems that increase the patient's risk for aortic dissections.

Troponin: an enzyme that may be measured in the blood. It is released by damage to the heart.

Vasculitis: inflammation of the blood vessel system, which includes veins, arteries, and capillaries