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The more you know about coronary artery disease (CAD) and angina, the better equipped you'll be to manage your condition and achieve a good quality of life. To that end, LifeHeart.com presents brief definitions for words you're likely to come across during diagnosis and treatment. Click on highlighted words for more glossary definitions.

ACS

See acute coronary syndrome.

Acute coronary syndrome (ACS)

A sudden and severe condition of the heart. Includes unstable angina, heart attack, or sudden cardiac death.

Adenosine triphosphate (ATP)

A chemical compound found in cells, which is a rich source of energy for the body.

Angina, angina pectoris

Pain or discomfort in the center of the chest behind the breastbone, triggered by physical or emotional stress. Angina can be serious and debilitating, and is marked by repeated and sometimes unpredictable attacks. Symptoms of angina can spread to the jaw, shoulder, back, or arms and can range from mild to severe. Angina occurs when the heart requires more oxygen-rich blood than the coronary arteries are able to supply, usually as a result of atherosclerosis. Angina pain or discomfort is usually relieved by rest and/or short-acting nitroglycerin.

Angiogenesis

The growth of new blood vessels. Researchers are experimenting with angiogenesis in some new treatments for coronary artery disease and angina. The goal is to stimulate more blood vessels to grow in the heart.

Angiography

An X-ray examination of blood vessels, following injection of a contrast dye, to find blockages in the arteries of the heart. Helps determine how much coronary artery disease is present.

Angioplasty

A procedure that opens coronary arteries that have been clogged by fatty plaques caused by coronary artery disease. A balloon at the tip of a catheter is inflated inside an artery and presses the plaque against the artery wall. Some angioplasty procedures also use a stent to help keep the artery open.

Angiotensin-converting enzyme inhibitor

A medication that blocks (or inhibits) a natural chemical in the body that narrows blood vessels and increases blood pressure. As a result, vessels relax and blood pressure decreases, allowing more oxygen-rich blood to reach the system

Aorta

The main artery of the body, which carries blood from the left ventricle to smaller arteries throughout the body. The aorta also supplies blood directly to the heart via the coronary arteries.

Aortic valve

The one-way valve between the left ventricle and the aorta.

Arrhythmia

An abnormal heart rhythm, or heartbeat. The rhythm can be too fast, too slow, or irregular (beating at an off-beat rhythm). Some arrhythmias aren't a problem, but more serious arrhythmias can mean the heart is working less effectively, and may cause symptoms of palpitations, weakness, dizziness, chest pain, and shortness of breath.

Artery

A blood vessel carrying oxygen-rich blood away from the heart to the body tissues.

Atherosclerosis

Hardening of the arteries. Fatty deposits called plaques form on the inner lining of the lumen. The narrowed passageway that results decreases the flow of oxygen-rich blood through the heart, which can increase the risk for angina.

ATP

See adenosine triphosphate.

Atria

More than one atrium.

Atrium

Either of the two upper chambers of the heart. Blood returned from the upper body to the heart from the veins enters the right atrium through the superior vena cava, and through the inferior vena cava from the lower body. The vena cava is the body's largest vein. Oxygen-rich blood is returned to the left atrium from the lungs.

Beta-blockers

Drugs used to treat chronic angina, high blood pressure, and other conditions. These medications may decrease the strength and rate of the heartbeat by blocking beta-receptors, which receive signals from the brain to make the heart work harder, for example, during exercise or emotional stress. By reducing the heart's workload, beta-blockers may decrease the amount of oxygen that the heart requires.

Bicuspid valve

The one-way valve between the left atrium and left ventricle.

Blood

A red fluid that circulates through the heart, arteries, capillaries, and veins and contains many types of cells, including red and white blood cells. It also carries oxygen and other nutrients to meet the body's energy needs, and removes carbon dioxide and waste products.

Blood pressure

The pressure of the blood against the walls of the arteries. Two numbers are recorded: the higher one measures pressure when the heart contracts to pump blood to the body; the lower one measures pressure when the heart relaxes between beats.

CABG

See coronary artery bypass graft.

CAD

See coronary artery disease.

Calcium channel blockers

Drugs used to treat chronic angina, high blood pressure, and other conditions. Calcium that enters cells can cause a tightening of the arteries, higher blood pressure, and increased workload on the heart. Calcium channel blockers may help reduce the amount of calcium that enters cells. Arteries are then able to widen, and blood pressure decreases. Some calcium channel blockers may help decrease the strength of the heartbeat, while others may decrease the rate of the heartbeat. Both methods may help decrease the workload on the heart and the amount of oxygen it requires to work effectively.

Capillaries

Small, narrow blood vessels that form bridges between arteries, which carry oxygen-rich blood away from the heart, and veins, which bring oxygen-depleted blood back to the heart. Capillaries carry blood to and from cells in the body, allowing for exchange of oxygen, nutrients, carbon dioxide, and cell waste.

Cardiac

A medical term referring to the heart.

Cardiac function modulators

Unlike the traditional drugs used to manage chronic angina, cardiac function modulators make the heart more efficient, do not depend on changes in heart rate or blood pressure, and help the heart work more efficiently when oxygen supply is limited.

Cardiac Syndrome X

Also called microvascular angina, this form of chest pain or discomfort occurs in the absence of any visible blockage of the arteries of the heart. The pain or discomfort may stem from smaller arteries that supply the heart but fail to function properly. Occurs in women more than men.

Cardiologist

A medical doctor, sometimes called a heart doctor, who specializes in diseases of the heart.

Cardiovascular system

The circulatory system, consisting of the heart and blood vessels.

CHF

See congestive heart failure.

Cholesterol

A fatty substance that occurs naturally in the blood, cell walls, and most body tissues. Cholesterol is made by the liver, and also enters the body via foods rich in saturated fat. Excess cholesterol collects in fatty deposits called plaques along artery walls, a major feature of coronary artery disease.

Chronic angina

Angina brought on by physical or emotional stress. "Chronic" means the condition has been present for a long time and is ongoing.

Conduction system

The electrical system of the heart. Electrical signals created in the conduction system stimulate the heart to beat (contract), pumping blood throughout the body. The speed and strength of the contraction are affected by signals from the central nervous system that help the body respond to its surroundings.

Congestive heart failure (CHF)

See heart failure.

Contraction

The beat of the heart, caused by a quick shortening of the heart muscle and resulting in the pumping of blood to the rest of the body.

Coronary arteries

Vessels that supply blood to the heart directly from the aorta.

Coronary artery bypass graft

A type of heart surgery (also called open heart surgery) that transplants a section of a vessel from another part of the body (usually from the leg or breast) to make a detour around a blockage in a coronary artery. The patient may be placed on a heart-lung bypass machine that lets a surgeon work on the non-beating heart.

Coronary artery disease (CAD)

A condition marked by a buildup of fatty plaques that narrows the coronary arteries and reduces the flow of oxygen-rich blood through the heart.

Demand angina

Angina pain or discomfort caused when blood flow through the heart is normal but the blood lacks enough oxygen for the heart's needs.

Diabetes

A disease caused by high levels of sugar in the bloodstream. High blood sugar may occur when the pancreas does not secrete enough insulin (Type 1 diabetes) or when the cells of the body stop responding to it (Type 2 diabetes). Diabetes may cause weight loss, frequent urination, excessive thirst and hunger, blurred vision, nausea, fatigue, or drowsiness.

ECG

See electrocardiogram.

Echocardiography

A test used to help diagnose heart failure. Also called an "Echo," noiseless sound waves are emitted from the machine towards the heart that create a picture of the chambers and the valves of the heart as it beats.

EKG

See electrocardiogram.

Electrocardiogram (ECG, EKG)

A recording of the electrical activity of the heart on a moving strip of paper. It helps determine how well and how fast the heart is working. Certain types of heart disease are associated with specific changes in the EKG recording.

Endocardium

The smooth inner tissue layer of the heart.

Exercise tolerance test (ETT)

A test that helps doctors diagnose angina. Under the supervision of a doctor, a patient exercises by walking on a treadmill or riding a bicycle while hooked up to an EKG machine. Sometimes called an exercise stress test.

ETT

See exercise tolerance test.

FDA

See Food and Drug Administration.

Food and Drug Administration (FDA)

The regulatory authority in the United States charged with protecting consumers by controlling the licensing and monitoring the use of all food, drugs, medical devices, and cosmetics.

Glucose

A type of sugar that is made in the body from the food we eat. It provides energy to the body’s cells.

Glucose Tolerance Test

This test is performed in a doctor’s office or lab to diagnose diabetes. After an overnight fast, patients drink a very concentrated sugar solution and have their blood sugar levels measured hourly for three hours. Women who may be at risk for developing diabetes during their pregnancy may take this test.

Graft

Any tissue or organ that is implanted or transplanted, including a section of a blood vessel used to make a detour around a blocked artery, such as during a coronary artery bypass graft.

HbA_1c test

A test done in a laboratory to determine what a person’s average blood sugar levels have been over the past two or three months.

HDL

See high-density lipoprotein.

Heart

The four-chambered, muscular organ found behind the breastbone and between the lungs. The four chambers include the right and left atria and the right and left ventricles. Blood enters the right half of the heart and is pumped into the lungs to obtain oxygen. Oxygen-rich blood returns from the lungs into the left side of the heart where it is pumped out to the rest of the body.

Heart attack

Sudden, severe chest pain that occurs when a portion of the heart no longer receives oxygen-rich blood, usually due to total or near-total blockage of a coronary artery by a blood clot formed in an area already narrowed by plaque. The surrounding heart muscle dies and the heart stops working effectively. Also called a myocardial infarction (MI). Heart attacks are part of the acute coronary syndrome.

Heart failure

A condition that causes the heart to pump blood less effectively than normal. As a result, fluid often collects in the lungs, leading to breathlessness and swelling of the legs and ankles. Common causes include chronic hypertension and heart attack.

Hemoglobin

A substance contained within red blood cells that carries oxygen from the lungs throughout the body. Hemoglobin is responsible for the color of red blood cells.

High blood pressure

Abnormally high pressure in the arteries that may not cause symptoms but can increase the risk of heart attack, stroke, and other illnesses. Continuously high blood pressure is called hypertension and often requires drug therapy and heart-healthy nutrition to keep blood pressure within normal limits.

High-density lipoprotein (HDL)

Termed "good cholesterol," a substance that carries cholesterol in the blood away from the arteries of the heart and other parts of the body back to the liver for removal. High levels of HDL are associated with a lower risk of developing coronary artery disease.

HMG-CoA reductase inhibitors

See statins.

Homocysteine

An amino acid that occurs naturally in the body. High levels are a risk factor for coronary artery disease. Homocysteine helps "bad cholesterol" (LDL) build fatty plaques in the coronary arteries.

Hyperlipidemia

The presence of high levels of fats in the bloodstream. Two types of fats are included—triglycerides and cholesterol (which includes LDL and HDL cholesterol), and the lipoproteins (including high-density lipoprotein and low-density lipoprotein).

Hypertension

A continuous increase in blood pressure above what is considered normal, often requiring drug therapy and heart-healthy nutrition to help keep blood pressure within normal limits. Also known as high blood pressure.

IHD

See ischemic heart disease.

Inflammation

A response to injury. Swelling is one sign of inflammation.

Insulin

A hormone produced by the pancreas. It is released after we eat to help control how much sugar is in the blood.

Ischemia

An inadequate supply of oxygen for the heart and other organs. Ischemia can be caused by low levels of oxygen in the blood, or reduced blood flow through the heart. Often related to coronary artery disease.

Ischemic heart disease (IHD)

A condition that prevents enough oxygen from being supplied to the heart. It is usually caused by the constriction (tightening) or narrowing of the coronary arteries supplying the heart.

LDL

See low-density lipoprotein.

Left anterior descending artery (LAD)

A large blood vessel that supplies parts of the left and right ventricles of the heart.

Left circumflex artery

A large vessel that supplies blood to parts of the left atrium and left ventricle.

Low-density lipoprotein (LDL)

Termed "bad cholesterol," this substance is actually a carrier protein that transports cholesterol in the blood. The cholesterol carried by LDL can attach to artery walls adding to plaque buildup already in progress. High levels of LDL are associated with an increased risk of developing coronary artery disease.

Lumen

The tubular space in blood vessels, such as the arteries, through which blood travels.

Metabolic syndrome

Also known as insulin-resistance syndrome, this is a group of heart disease risk factors that may place a person at risk for heart disease. A person may have metabolic syndrome if at least three of the five following conditions are present: excessive weight around the waist, high blood pressure, low levels of HDL, high fasting glucose levels or high levels of triglycerides..

MI

See myocardial infarction.

Microvasculature

The body's network of smaller, finer blood vessels.

MID-CAB

See minimally invasive coronary artery bypass graft.

Millimeters of mercury (mm Hg)

Units of pressure used to evaluate blood pressure. Though modern machines measure blood pressure digitally, the original blood pressure measurement devices used mercury (hence, "millimeters of mercury") to measure changes in pressure.

Minimally invasive coronary artery bypass graft (MID-CAB)

A type of heart surgery that is less invasive than traditional open heart surgery. A surgeon makes a small incision into the chest, rather than cutting the breastbone and opening up the whole chest, to perform a coronary artery bypass graft. The surgeon uses video monitors to guide the surgery.

Myocardial infarction (MI)

Sudden, severe chest pain that occurs when a portion of the heart no longer receives oxygen-rich blood, usually due to total or near-total blockage of a coronary artery by a blood clot formed in an area already narrowed by plaque. The surrounding heart muscle dies and the heart stops working effectively. Also known as a heart attack. A myocardial infarction is part of the acute coronary syndrome.

Myocardium

The muscle layer of the heart.

Nitrates

Drugs used to treat chronic angina. Nitrates may help relax blood vessels, lower blood pressure, and increase blood flow to the heart. Nitroglycerin is a well-known nitrate doctors prescribe for angina.

Nitroglycerin

A common form of the drug class called nitrates, prescribed to control angina attacks. Nitroglycerin comes in both short- and long-acting forms.

Non-exercise stress test

A doctor-supervised test for people who may be unable to exercise hard enough to do a meaningful treadmill or bicycle exercise tolerance test. Stress tests use drugs instead of exercise to trigger angina or angina-like symptoms, helping doctors diagnose the condition.

Occlusion

The obstruction or closing of a blood vessel that can be associated with coronary artery disease.

Off-pump coronary artery bypass graft (OP-CAB)

A type of heart surgery to restore healthy blood flow to repair a blocked artery that does not require the patient to be placed on a heart-lung bypass machine. Instead, surgeons use a mechanical device to restrict heart movement in the small area where they connect a new detour blood vessel in the heart. The new vessel is usually taken from the leg or breast. The off-pump coronary artery bypass graft surgery may reduce the length of time the patient stays in the hospital, as well as the risk of complications compared with traditional open heart surgery.

OP-CAB

See off-pump coronary artery bypass graft.

Open heart surgery

A type of heart surgery that transplants a section of a vessel from another part of the body (usually from the leg or breast) to make a detour around a blockage in a coronary artery. The patient is placed on a heart-lung bypass machine that lets the surgeon work on the non-beating heart. Also called coronary artery bypass graft (CABG).

Oxygen

A gas in the atmosphere that is essential to most life forms. In humans, oxygen is absorbed into the lungs from the air we breathe. It attaches to hemoglobin in red blood cells in the blood to be carried throughout the body.

PCI

See percutaneous coronary intervention.

Pericardium

The fluid-filled outer sac of the heart.

Percutaneous coronary intervention (PCI)

A type of heart procedure that includes both a balloon angioplasty (percutaneous transluminal coronary angioplasty, or PTCA) and stents. The balloon is used to open a blocked artery. The stent is used to help keep the artery open after the balloon is removed.

Percutaneous transluminal coronary angioplasty (PTCA)

A type of heart procedure used to open narrowed blood vessels. A balloon is inserted into the narrowed artery where it is inflated, pressing fatty plaque against the wall of the artery. This helps increase the size of the lumen and improve blood flow to the heart.

Plaques

The fatty buildup that develops on the inner walls of arteries, narrowing the lumen and reducing the flow of oxygen-rich blood to the heart. Plaque buildup due to atherosclerosis usually leads to coronary artery disease.

Platelets

A blood cell with sticky or adhesive qualities that helps the blood to clot. Platelets can attach to plaques that form on artery walls, which can help start or worsen plaque buildup.

Prinzmetal's angina

See variant angina.

PTCA

See percutaneous transluminal coronary angioplasty.

Pulmonary valve

The one-way valve between the right ventricle and the lungs.

Pulse

The beating felt in the blood vessels caused by the contraction of the heart.

Quality of life

Used in the context of a medical condition, quality of life refers to the overall status of a combination of factors: a person's health, symptoms, and level of physical and social functioning. If an illness and its treatment have a negative impact on a person's sense of well-being and ability to perform daily activities, then quality of life may be poor.

Radionuclide imaging

A test used to help diagnose heart failure. Doctors inject a harmless radioactive dye into the blood that attaches to red blood cells. The radioactive dye is visible through a special camera that is able to follow the dye through the heart and the rest of the body. The test helps doctors measure the pumping efficiency of the heart.

Red blood cells

Also called erythrocytes, red blood cells contain hemoglobin, which enables them to carry oxygen throughout the body.

Reocclusion

The obstruction or closing of a blood vessel that may occur after open heart surgery.

Restenosis

Narrowing of a blood vessel that may occur after a percutaneous coronary intervention is done to open the blockage.

Revascularization

The surgical method of opening up blocked blood vessels to improve blood flow to the heart.

Right coronary artery

A large vessel that supplies blood to the right side of the heart.

Risk factors

Clearly defined characteristics (such as family history, weight, or the results of certain blood tests, among others) known to increase the chance of developing a certain disease.

Silent ischemia

Angina attacks without angina pain or discomfort are called silent ischemia. Ischemia means not enough oxygen is available for the heart to work effectively.

Statins

A drug class (called HMG-CoA reductase inhibitors) that may help reduce levels of LDL ("bad cholesterol") in the blood. Often prescribed to patients with high cholesterol levels who have a history of heart attack or who are at risk.

Stenosis

An abnormal narrowing of a lumen, such as in a coronary artery.

Stent

Hollow wire mesh placed inside a blood vessel during a percutaneous coronary intervention. Opening the stent within an artery presses the plaque against the artery wall and helps maintain an open lumen.

Sudden cardiac death

An unexpected death from cardiac arrest, or abrupt loss of heart function. The person may not have been previously diagnosed with heart disease, but the most common cause is coronary artery disease. Sudden cardiac death is part of acute coronary syndrome . Also called sudden death.

Supply angina

Angina pain or discomfort caused by a reduced flow of oxygen-rich blood through the heart.

Tricuspid valve

The one-way valve between the right atrium and the right ventricle.

Triglycerides

Triglycerides store energy, which is housed in fatty tissue and is gradually released between meals to meet the body's needs. High levels of triglycerides in the blood may be associated with coronary artery disease.

Unstable angina

Severe and unpredictable angina in which the severity, frequency, or length of angina attacks suddenly increases. Attacks may occur during periods of exercise or rest. It results from the sudden or complete blockage of an artery in the heart. Unstable angina is part of acute coronary syndrome.

Variant angina

A type of angina that only occurs at night or in early morning and is due to a spasm (rapid tightening) of a coronary artery. Attacks may occur while at complete rest, while strenuous physical activities can sometimes be performed without experiencing angina pain or discomfort.

Vein

A blood vessel through which blood passes from various body tissues back to the heart. All veins, except the pulmonary veins, carry blood low in oxygen.

Ventricle

Either of the two lower chambers of the heart. The right ventricle pumps oxygen-poor blood to the lungs. The blood absorbs oxygen in the lungs and returns to the heart. Then the left ventricle pumps the newly oxygen-rich blood through the body.

Vessel

Any channel that carries blood throughout the body. Three types of blood vessels, the arteries, capillaries, and veins, make up the network of vessels called the vasculature.

White blood cells

Infection-fighting blood cells; they defend the body from invaders such as viruses and bacteria. Also called leukocytes.

Sources

1. Stedman's Medical Dictionary, 27th Edition, Lippincott Williams & Wilkins, 2000.
2. Dorland's Illustrated Medical Dictionary, 29th Edition, W.B. Saunders Company, 2000.