Ablation
A therapeutic method that uses a form of energy to physically destroy a small section of heart tissue that is contributing to or causing some types of fast heartbeats (tachycardia). Most often it is used to treat rapid heartbeats in the upper chambers of the heart rather than the lower chambers.

Anticoagulants (Blood Thinners)
A group of drugs that are used to treat certain blood vessel, heart and lung conditions by decreasing the ability of blood to clot or coagulate. Although sometimes called “blood thinners” they do not actually “thin” the blood. People at high risk for developing blood clots, such as those with artificial heart valves or who have atrial fibrillation are given anticoagulants.

Aortic Stenosis (AS)
Aortic stenosis is the narrowing or obstruction of the heart's aortic valve, which prevents it from opening properly and blocks the flow of blood from the left ventricle to the aorta. Aortic stenosis may be present from birth (congenital), or it may develop later in life (acquired). It is caused by many disorders.

Aortic Valve
The heart valve located between the aorta and the left ventricle. The normal aortic valve usually has three leaflets that open and close together.

Arrhythmia (Dysrhythmia)
A disorder of the regular rhythmic beating of the heart. Arrhythmias result in ineffective and uncoordinated contractions of the heart muscle and may cause a slow, rapid or irregular pulse.

Atrial Fibrillation
A disorder of the heart rate and rhythm. During atrial fibrillation, the heart's two small upper chambers (the atria) quiver instead of beating effectively. Blood isn't pumped completely out of them, so it may pool and clot. If a piece of a blood clot in the atria leaves the heart and becomes lodged in an artery in the brain, a stroke results.

Atrial Flutter
When the heart’s upper chambers (atria) beat very rapidly this is called atrial flutter. Most often this occurs in people with heart diseases like pericarditis, coronary artery disease and cardiomyopathy.

Bicuspid Aortic Valve
Normally the aortic valve (the valve between the left ventricle and the aorta) has three flaps (also known as leaflets or cusps). A bicuspid aortic valve is a congenital heart defect that occurs when the aortic valve has only two flaps. Patients with this may develop a narrowed or leaking aortic valve.

Blood Clot
Blood clots or coagulates into a jelly-like mass called a blood clot. A blood clot is desirable to stop bleeding caused by an injury, but can become very dangerous if it occurs within the bloodstream. A blood clot can form when plaque deposits in blood vessel walls rupture. If a piece of the blood clot breaks away and gets in the bloodstream, it can cause a heart attack or stroke by blocking the flow of blood to the heart, brain, or other vital organs.

Cardiopulmonary Bypass
A mechanical device, also called the heart/lung machine that is used during cardiac surgical procedures to safely stop the heart. It drains the blue or oxygen-poor blood from a patient, puts it in a reservoir where oxygen is added and then pumps this red or oxygen-rich blood directly back into the patient’s aorta.

Coronary Artery Bypass Graft (Bypass Surgery)
To improve the supply of blood and oxygen to the heart muscle, surgery reroutes or bypasses blood around clogged arteries. This is sometimes called open-heart surgery or CABG (pronounced cabbage) for coronary artery bypass graft.

Echocardiography
A test that uses sound waves to create a moving picture of the heart. The picture is much more detailed than an X-ray image and involves no radiation exposure.

Electrocardiogram (ECG or EKG)
A test that places electrodes on the arms, legs and chest to measure the rate and regularity of heartbeats as well as the size and position of the chambers, the presence of any damage to the heart, and the effects of drugs or devices used to regulate the heart (such as a pacemaker).

Embolus
A blood clot that moves through the bloodstream until it lodges in a narrowed vessel and blocks circulation (the flow of blood).

Endocarditis
Endocarditis is an inflammation of the inside lining of the heart chambers and heart valves (endocardium). This is usually caused by a bacterial infection. People at an increased risk include those with prosthetic heart valves, abnormal heart valves, or a history of endocarditis or congenital heart defects.

Fibrillation
Fast, uncoordinated contractions of individual heart muscle fibers where the heart chamber involved pumps blood ineffectively if at all.

Heart Murmur
An abnormal sound in the heart such as blowing, whooshing, or rasping sounds caused by a defective heart valve or holes in the heart. The sound is produced by turbulent blood flow through the heart valves or near the heart.

Heart Rate
The number of heartbeats per minute. Also known as pulse. The heart normally beats 60-100 times a minute.

Heart Valve
Controls the direction of blood flow through the heart. There are four valves in the heart, the tricuspid valve, pulmonary valve, mitral valve and aortic valve. They open and close with each heartbeat and permit the blood to flow in only one direction.

Heart Valve Repair Surgery
Heart valve repair surgery is a procedure used to fix a person's malfunctioning heart valve as opposed to replacing it with either a mechanical or tissue valve. Different techniques can be used depending on the problem the person has.

Heart Valve Replacement Surgery (Artificial Heart Valve Surgery)
Open-heart valve replacement surgery is done to remove a person’s native valve that is damaged from disease or long-term wear. The person’s own valve is removed and replaced with an artificial (prosthetic) valve or an allograft (donated tissue from a person who has dies). There are two types of artificial valves: tissue (biological) valves or mechanical (metal or hard carbon) valves.

Heart Valve Repair Surgery
Heart valve repair surgery is a procedure used to fix a person's malfunctioning heart valve as opposed to replacing it with either a mechanical or tissue valve. Different techniques can be used depending on the problem the person has.

Magnetic Resonance Imaging (MRI)
A non-invasive procedure that uses powerful magnets and radio waves to construct pictures of the body. In congenital heart disease it is used to reconstruct images of the heart, blood vessels, lungs and trachea.

Maze Procedure
A surgical procedure where a number of lesions are made in the atria of the heart to control atrial fibrillation and/or atrial flutter. The maze procedure is frequently performed with other necessary cardiac surgery, such as coronary artery bypass and valve repair or replacement.

Mechanical Heart Valve (Metal or Hard Carbon Valve)
Mechanical valves are made of hard, durable materials that have been proven to be safe for use in the human body.

Mitral Valve
The mitral valve has two flaps (cusps or leaflets) that open and close similar to a double door. It is located between the heart’s upper left chamber (atrium) and lower left chamber (ventricle).

Mitral Valve Prolapse (MVP)
A heart problem in which the valve that separates the left upper and lower chambers of the heart does not open and close properly. This sometimes lets a small amount of blood leak backward through the valve.

Mitral Valve Stenosis
Stenosis is the narrowing of an opening. Mitral valve stenosis is a heart condition in which the mitral valve fails to open as wide as it should. This can cause a backup of blood and fluid in the lungs.

Open Heart Surgery
Any surgery where the chest is opened and surgery is performed on the heart. The term “open” refers to the chest, not the heart itself. The heart may or may not be opened, depending on the type of surgery. The surgery is performed using cardiopulmonary bypass.

Pulmonic (Pulmonary) Valve
The heart valve between the right ventricle and the pulmonary artery that separates the heart from the pulmonary artery.

Regurgitation
When a heart valve doesn’t close properly it lets blood leak (regurgitate) back into the chamber it was pumped from.

Stenosis
An abnormal narrowing in a blood vessel or a native heart valve.

Thrombosis
A blood clot that forms or is already present in a blood vessel or chamber of the heart.

Thrombus
A blood clot that forms in a vessel or within the heart and remains there is called a thrombus.

Tissue Valve (Biological)
Tissue heart valves are made from animal tissue such as pigs or cows. They closely resemble the person’s own valve that was not functioning properly and required replacement.

Transesophageal Echocardiography (TEE)
A diagnostic test using an ultrasound device that is passed into the esophagus to create a clear image of the heart muscle and other parts of the heart from behind.

Tricuspid Valve
The heart valve located on the right side of the heart, between the right atrium and the right ventricle. The normal tricuspid valve usually has three leaflets and three papillary muscles.