Heart glossary

Here are some terms your doctor may use when he or she is talking to you about your heart:

Angina pectoris or angina:

Literally “chest pain,” this is a condition in which the heart muscle doesn’t get enough blood to fuel the work that it’s doing, resulting in chest pain, and often pain in the left arm and shoulder. The most common cause is atherosclerosis, which narrows the coronary arteries and restricts the flow of blood.


A drug that prevents blood from clotting. When such a drug is given in cases where a blood vessel is plugged up by a clot, it tends to prevent new clots from forming or prevents the existing clot from enlarging. It does not dissolve an existing clot.


The main trunk artery that receives blood from the lower left chamber of the heart. It begins at the base of the heart, arches up over the heart like the handle of a walking cane and passes down through the chest and abdomen in front of the spine. It branches off into many lesser arteries that conduct blood to every part of the body, except the lungs.

Arteriogram (coronary):

X-ray films of the coronary arteries are made by injecting an opaque X-ray dye into the veins to trace the flow of blood through the heart’s arteries.


Blood vessels that carry blood away from the heart to various parts of the body. They usually carry oxygenated blood, except for the pulmonary artery, which delivers un-oxygenated blood from the heart to the lungs, where it’s oxygenated.


Commonly called hardening of the arteries, this is a generic term for a variety of conditions that cause the artery walls to thicken and lose elasticity.


A type of arteriosclerosis in which the inner walls of an artery become coated with thick, irregular deposits of a fatty substance. These deposits decrease the diameter of the blood vessel and restrict the flow of blood.


A fat-like substance that’s found in all cells of the body. The ideal cholesterol level for Americans is below 200 milligrams per 100 cubic centimeters. A higher-than-normal level of cholesterol increases the risk of coronary atherosclerosis.

Collateral circulation:

Detoured circulation of the blood through similar vessels when a main vessel has been blocked off.

Coronary arteries:

Two arteries, arising from the aorta, that arch down over the top of the heart, branch and conduct blood to the heart muscle.

Coronary artery disease or coronary atherosclerosis:

A build-up of fatty materials inside the arteries that conduct blood to the heart muscle. The diameter of the inner walls of these coronary arteries is narrowed and the blood supply to the heart is reduced.

Coronary occlusion:

An obstruction (usually a blood clot) in a branch of one of the coronary arteries that hinders blood flow to part of the heart muscle. This part of the heart muscle then dies because of the reduced blood flow. Also called a coronary, heart attack or coronary heart attack.

Coronary thrombosis:

A form of coronary occlusion, this is the formation of a clot in a branch of one of the coronary arteries that conduct blood to the heart muscle.


Often abbreviated ECG or EKG, this is a graphic record of the electric currents produced by the heart.


A local, usually temporary deficiency of blood in some part of the body, often caused by a constriction or blockage in the blood vessels.

Myocardial Infraction:

Death or damage to an area of the heart muscle (myocardium) because of an inadequate blood supply to that region.


The muscular wall of the heart. The thickest of the three layers of the heart wall, it lies between the inner layer (endocardium) and the outer layer (epicardium).


A drug (a vasodilator) that relaxes the muscles in the blood vessels and allows them to expand. It’s often used to relieve attacks of angina pectoris and spasms of the coronary arteries.

Polyunsaturated fat:

A fat that’s usually a liquid oil of vegetable origin, such as corn or safflower oil, which is chemically constituted to absorb additional hydrogen. Diets high in polyunsaturated fat tend to lower the amount of blood cholesterol and lessen the hazard of fatty build-up within the blood vessels. That’s why those at risk of heart disease partially substitute them for saturated fat in the diet.

Saturated fat:

A fat – usually a solid fat of animal origin such as in milk, butter, meat – that’s chemically constituted so that it can’t absorb more hydrogen. A diet high in saturated fat tends to increase the amount of blood cholesterol. These fats are restricted in the diet to reduce the hazard of fatty deposits building up inside the blood vessels.


Either of the two lower chambers of the heart. The left ventricle pumps oxygenated blood through the arteries to the body, while the right ventricle pumps un-oxygenated blood through the pulmonary artery to the lungs. The capacity of the ventricles is usually about 120-130 cubic centimeters, or 8 1/2 tablespoons of blood, although they can accommodate more during exercise.