Heart Institute Glossary

Ablation: As applied to Interventional Cardiology, this is a nonsurgical procedure in which a catheter is inserted through the veins to the heart. Through the catheter, an electrical charge is delivered that eliminates areas of the heart muscle or conduction system that cause the heart to beat too fast or irregularly.

Angina: Chest pain or a sensation of pressure that occurs when the heart muscle is not getting enough oxygen.

Anticoagulants: Drugs (such as heparin or coumadin) that cause the blood to take longer to clot. They are often called "blood thinners."

Aorta: The main artery leading from the heart to the rest of the body.

Aortic insufficiency (regurgitation): Leakage or backflow of blood from the aorta through the aortic valve into the left ventricle.

Aortic stenosis: A narrowing of the opening of the aortic valve that blocks the flow of blood from the left ventricle into the aorta.

Arrhythmias: Irregularities in heart rhythm in which the heart can beat either too fast (tachycardia) or too slow (bradycardia). Arrhythmias may reduce the heart's ability to pump efficiently.

Arteries: The vessels that branch from the aorta. They carry oxygen-rich blood throughout the body.

Arteriosclerosis: A condition in which the walls of the arteries become thick and hard, losing the ability to stretch and contract in response to changes in blood pressure or the heart's pumping action. Arteriosclerosis is also known as "hardening of the arteries."

Atherosclerosis: Narrowing or blockage caused by a buildup of fatty plaque made up of cholesterol and other materials inside the walls of the arteries.

Beating-heart surgery Cardiac surgery done without cardiopulmonary bypass. The heart continues to beat during the surgery but all or part may be temporarily stabilized to allow the surgeon to work.

Blood pressure: A measurement of the two forces that moving blood puts on the artery wall. Systolic pressure is a measure of the greatest pressure on the arteries that occurs when the heart pumps blood out into the body. Diastolic pressure is a measure of the lowest pressure on the arteries that occurs between heartbeats.

A condition in which the muscles of the heart become thicker and stiffer, which leads to the heart to beat less efficiently. It may be caused by long-standing heart disease, viruses, toxic effects of alcohol or unidentified factors.

Catheter: A small plastic tube used to inject liquid (dye) into the coronary artery during a coronary angiogram or angioplasty/stent.

Cholesterol: A waxy, fat-like substance made by the bodies of humans and animals. It is found in meat, eggs and dairy products. A total cholesterol test measures several types of blood fats. One type is low-density lipoproteins that increase the plaque deposited inside the arteries and raises the risk of atherosclerosis. Another is high-density lipoproteins. These help carry fat away from artery walls. Triglycerides are a third type factored into a total cholesterol reading. The higher the triglycerides are, the greater the chances of developing atherosclerosis.

Congestive heart failure: A condition in which the heart muscle is unable to effectively pump blood out to the rest of the body, causing blood to collect in the chambers of the heart and the lungs.

Coronary arteries: Vessels that supply blood and oxygen to the muscles of the heart. They branch off of the aorta and run across the surface of the heart.

Coronary arteriography: A diagnostic procedure in which dye is injected into the coronary arteries to highlight them on an X-ray, allowing the doctor to see blockages or abnormal narrowing.

Coronary artery bypass graft (CABG): A type of open heart surgery in which pieces of a vein or artery are used to route blood flow around a blockage in one or more of the arteries that supply oxygen to the heart muscle.

Coronary artery disease (CAD): A condition in which a coronary artery is clogged by cholesterol and fatty deposits. Clogged arteries may potentially reduce the supply of oxygen-rich blood to the heart muscle and lead to symptoms such as angina or exercise limitations, and can contribute to a heart attack (myocardial infarction).

Coronary thrombosis: A blood clot in an artery that blocks the supply of blood to the heart muscle leading to myocardial infarction.

Diuretics: Drugs that help the kidneys filter out and release excess water and salt from the blood. Diuretics are often used to help manage high blood pressure. These are commonly called "water pills."

Echocardiography: A procedure in which soundwaves are used to evaluate the structure of the heart, how the heart's valves and muscles are working and the size of the lower chambers of the heart (the ventricles).

Electrophysiology study (EPS): A procedure in which a catheter is inserted into the veins and up to heart to study the electrical activity of the heart. If abnormal heart rhythms are found, the site where they start from can be identified and the most appropriate treatment applied.

High blood pressure (hypertension): A condition in which the pressure of the blood pumping through the arteries is abnormally high. High blood pressure is often considered a "silent killer" because symptoms do not appear for years until a vital organ is threatened. Over time, high blood pressure can damage the heart, brain, eyes and kidneys. It can be caused (or made worse) by a variety of factors, including heart failure or disease, stress, too much salt, obesity, smoking or genetics.

Implantable cardioverter defibrillator (ICD): An electronic device placed inside the body to control life-threatening abnormal heart rhythms.

Invasive procedures: Procedures that involve puncturing or cutting open the skin or inserting an instrument into the body.

Ischemia: A condition in which the supply of blood (and thus oxygen) to the heart muscle is not high enough for the heart to function normally.

Mitral insufficiency (regurgitation): A leak or flow of blood back through the mitral valve into the top left chamber of the heart (the atrium). It occurs when the mitral valve does not completely close.

Mitral valve stenosis: A condition in which the opening of the mitral valve is blocked or narrowed, preventing blood from completely flowing out of the heart's upper left chamber (left atrium) and causing blood to collect in the atrium and the lungs.

Monounsaturated fats: A type of fat that comes from plants and vegetables and is liquid at room temperature. It includes olive oil, canola oil, peanut oil and avocados. This type of fat can help lower blood cholesterol levels.

Myocardial infarction: A condition in which the muscles of the heart are killed or damaged because they do not get enough blood and oxygen. Also known as a heart attack, it happens when there is a blockage of the blood vessels that supply the heart.

Open heart surgery: Heart surgery where the chest is opened to expose the heart.

Pacemaker: A device placed in the body that sends out electrical signals to keep the heart beating at a speed appropriate for the body's needs

Pacemaker-cardioverter defibrillator (PCD): An electronic device placed inside the body to sense and stop an abnormal, potentially life-threatening heart rhythm. It also regulates the speed of the heartbeat to meet the body's needs.

Percutaneous transluminal coronary angioplasty (PTCA): A procedure used to widen partially blocked coronary arteries using a small balloon that is inflated in the narrowed section of the coronary artery.

Plaque: A deposit containing cholesterol that thickens the walls of the arteries or blocks the inside of the vessel.

Polyunsaturated fats: A type of fat from plants or vegetables that is usually soft at room temperature, including cottonseed, soybean, corn oil and safflower oil. Polyunsaturated fats can help lower blood cholesterol levels.

Resting electrocardiography: A recording of the heart's electrical activity at rest.

Saturated fats: A type of fat that is usually solid at room temperature. Most saturated fats come from animal sources, such as beef, veal, lamb, poultry, milk, butter, cheese and lard. There are also plant-based saturated fats, such as vegetable shortening and palm and coconut oils. Saturated fats raise blood cholesterol levels.

Sheath: A small catheter or tube that allows for access into a vein or artery during catheterization, angiography, angioplasty and electrophysiology study procedures. It is usually removed immediately after the procedure, although for an angioplasty, it may be left in place several hours.

Stress electrocardiography: Recording of the heart's electrical activity while the patient exercises.

Thrombolysis: A process of dissolving clots that clog arteries.

Transesophageal echocardiography: A type of echocardiography in which the device that generates the soundwaves that are to be measured is placed in the esophagus through the mouth.

Valvuloplasty: A nonsurgical procedure to widen narrowed or tight heart valves.

Vasodilators: Drugs used to widen (dilate) blood vessels.