Brief definitions of heart-related words used to describe the heart and blood vessels as well as cardiovascular diseases and their prevention and treatments.
Acquired heart disease - Heart disease that arises after birth, usually from infection or through the build-up of fatty deposits in the arteries that feed the heart muscle.
Acute coronary syndrome (ACS) - refers to any group of symptoms compatible with acute myocardial ischemia and includes unstable angina, non—ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI).
Aneurysm - A sac-like protrusion from a blood vessel or the heart, resulting from a weakening of the vessel wall or heart muscle.
Angina or angina pectoris - Chest pain that occurs when diseased blood vessels restrict blood flow to the heart.
Arrhythmia (or dysrhythmia) - An abnormal heartbeat.
Arrhythmogenic right ventricular dysplasia (ARVD) - ARVD is a type of cardiomyopathy with no known cause. It appears to be a genetic condition (passed down through a family's genes). ARVD causes ventricular arrhythmias.
Arteritis - Inflammation of the arteries.
Arteriosclerosis - A disease process, commonly called "hardening of the arteries", which includes a variety of conditions that cause artery walls to thicken and lose elasticity.
Atherosclerosis - A disease process that leads to the buildup of a waxy substance, called plaque, inside blood vessels.
Atrial Fibrillation characterized by rapid and irregular beating (arrhythmia). Often it starts as brief periods of abnormal beating which become longer and possibly constant over time. It can lead to blood clots, stroke, heart failure and other heart-related complications.
Atrial flutter - A type of arrhythmia in which the upper chambers of the heart (the atria) beat very fast, causing the walls of the lower chambers (the ventricles) to beat inefficiently as well.
Atrial tachycardia - A type of arrhythmia that begins in the heart's upper chambers (the atria) and causes a very fast heart rate of 160 to 200 beats a minute. A resting heart rate is normally 60 to 100 beats a minute.
Atrioventricular block - An interruption or disturbance of the electrical signal between the heart's upper two chambers (the atria) and lower two chambers (the ventricles).
Bacteria - Germs that can lead to disease.
Bacterial endocarditis - A bacterial infection of the lining of the heart's chambers (called the endocardium) or of the heart's valves.
Blood clot - A jelly-like mass of blood tissue formed by clotting factors in the blood. Clots stop the flow of blood from an injury. Clots can also form inside an artery when the artery's walls are damaged by atherosclerotic buildup, possibly causing a heart attack or stroke.
Blood pressure - The force or pressure exerted by the heart in pumping blood; the pressure of blood in the arteries.
Bradycardia - Abnormally slow heartbeat.
Bundle branch block - A condition in which parts of the heart's conduction system are defective and unable to conduct the electrical signal normally, causing an irregular heart rhythm (arrhythmia).
Cardiac - Pertaining to the heart.
Cardiac amyloidosis - A disorder caused by deposits of an abnormal protein (amyloid) in the heart tissue, which make it hard for the heart to work properly. Also called "stiff heart syndrome."
Cardiac arrest - The stopping of the heartbeat, usually because of interference with the electrical signal (often associated with coronary heart disease).
Cardiac cachexia - A term for the muscle and weight loss caused by severe heart disease. It is often related to the depressed cardiac output associated with end-stage heart failure, but it can also occur with severe coronary artery disease.
Cardiac output - The amount of blood the heart pumps through the circulatory system in one minute.
Cardiologist - A doctor who specializes in the study of the heart and its function in health and disease.
Cardiology - The study of the heart and its function in health and disease.
Cardiomegaly - An enlarged heart. It is usually a sign of an underlying problem, such as high blood pressure, heart valve problems, or cardiomyopathy.
Cardiomyopathy - A disease of the heart muscle that leads to generalized deterioration of the muscle and its pumping ability.
Cardiovascular (CV) - Pertaining to the heart and blood vessels that make up the circulatory system.
Cardiovascular Disease (CVD) - A general term referring to conditions affecting the heart (cardio) and blood vessels (vascular system). May also simply be called heart disease. Examples include coronary artery disease, valve disease, arrhythmia, peripheral vascular disease, congenital heart defects, hypertension, and cardiomyopathy. Refer to specific conditions for detailed explanations.
Cholesterol - An oily substance that occurs naturally in the body, in animal fats and in dairy products, and that is transported in the blood. Limited amounts are essential for the normal development of cell membranes. Excess amounts can lead to coronary artery disease.
Circulatory system - Pertaining to circulation of blood through the heart and blood vessels.
Congenital heart defects - Malformation of the heart or of its major blood vessels present at birth.
Congestive heart failure or heart failure (CHF) - A condition in which the heart cannot pump all the blood returning to it, leading to a backup of blood in the vessels and an accumulation of fluid in the body's tissues, including the lungs.
Coronary artery anomaly (CAA) - A congenital defect in one or more of the coronary arteries of the heart.
Coronary artery disease (CAD) - A narrowing of the arteries that supply blood to the heart. The condition results from a buildup of plaque and greatly increases the risk of a heart attack.
Coronary heart disease - Disease of the heart caused by a buildup of atherosclerotic plaque in the coronary arteries that can lead to angina pectoris or heart attack.
Coronary occlusion - An obstruction of one of the coronary arteries that hinders blood flow to the heart muscle.
Coronary thrombosis - Formation of a clot in one of the arteries carrying blood to the heart muscle. Also called coronary occlusion.
Deep vein thrombosis - A blood clot in a deep vein in the calf (DVT).
Defibrillator - A device that helps restore a normal heart rhythm by delivering an electric shock.
Diastolic blood pressure - The lowest blood pressure measured in the arteries. It occurs when the heart muscle is relaxed between beats.
Dissecting aneurysm - A condition in which the layers of an artery separate or are torn, causing blood to flow between the layers. Dissecting aneurysms usually happen in the aorta, the large vessel that carries blood from the heart to other parts of the body and can cause sudden death.
Dyspnea - Shortness of breath.
Edema - Swelling caused by fluid accumulation in body tissues.
Embolus - Also called embolism; a blood clot that forms in a blood vessel in one part of the body and travels to another part.
Endocarditis - A bacterial infection of the heart's inner lining (endothelium).
Enlarged heart - A state in which the heart is larger than normal because of heredity, long-term heavy exercise, or diseases and disorders such as obesity, high blood pressure, and coronary artery disease.
Fibrillation - Rapid, uncoordinated contractions of individual heart muscle fibers. The heart chamber involved can't contract all at once and pumps blood ineffectively, if at all.
First-degree heart block - Occurs when an electrical impulse from the heart's upper chambers (the atria) is slowed as it moves through the atria and atrioventricular (AV) node.
Flutter - The rapid, ineffective contractions of any heart chamber. A flutter is considered to be more coordinated than fibrillation.
Fusiform aneurysm - A tube-shaped aneurysm that causes the artery to bulge outward. Involves the entire circumference (outside wall) of the artery.
Heart attack - Death of, or damage to, part of the heart muscle caused by a lack of oxygen-rich blood flowing to the heart.
Heart block - General term for conditions in which the electrical impulse that activates the heart muscle cells is delayed or interrupted somewhere along its path.
Heart failure - See congestive heart failure.
Heart murmur - An abnormal heart sound caused by turbulent blood flow. The sound may indicate that blood is flowing through a damaged or overworked heart valve, that there may be a hole in one of the heart's walls, or that there is a narrowing in one of the heart's vessels. Some heart murmurs are a harmless type called innocent heart murmurs.
Hemochromatosis - A disease in which too much iron builds up in your body (iron overload). Too much iron in the heart can cause irregular heartbeats (arrhythmias) and heart failure. Too much iron in the pancreas can lead to diabetes.
High blood pressure - A chronic increase in blood pressure above its normal range.
High density lipoprotein (HDL) - A component of cholesterol, HDL helps protect against heart disease by promoting cholesterol breakdown and removal from the blood; hence, its nickname "good cholesterol."
Hypertension - High blood pressure.
Hypertrophic obstructive cardiomyopathy (HOCM) - An overgrown heart muscle that creates a bulge into the ventricle and impedes blood flow.
Hyperventilation - Rapid breathing usually caused by anxiety. People feel like they can't get enough air, so they breathe heavily and rapidly, which can lead to numb or tingly arms and legs, or fainting.
Hypotension - Abnormally low blood pressure.
Incompetent valve - Also called insufficiency; a valve that is not working properly, causing it to leak blood back in the wrong direction.
Infarct - The area of heart tissue permanently damaged by an inadequate supply of oxygen.
Infective endocarditis - An infection of the heart valves and the innermost lining of the heart (the endocardium), caused by bacteria in the bloodstream.
Ischemic heart disease - Also called coronary artery disease and coronary heart disease, this term is applied to heart problems caused by narrowing of the coronary arteries, thereby causing a decreased blood supply to the heart.
Low density lipoprotein (LDL) - The body's primary cholesterol-carrying molecule. High blood levels of LDL increase a person's risk of heart disease by promoting cholesterol attachment and accumulation in blood vessels; hence, the popular nickname "bad cholesterol."
Mitral stenosis - A narrowing of the mitral valve, which controls blood flow from the heart's upper left chamber to its lower left chamber. May result from an inherited (congenital) problem or from rheumatic fever.
Mitral valve prolapse - A condition that occurs when the leaflets of the mitral valve between the left atrium and left ventricle bulge into the atrium and permit backflow of blood. The condition can be associated with progressive mitral regurgitation.
Murmur - Noises superimposed on normal heart sounds. They are caused by congenital defects or damaged heart valves that do not close properly and allow blood to leak back into the chamber from which it has come.
Myocardial infarction - A heart attack. The damage or death of an area of the heart muscle (myocardium) resulting from a blocked blood supply to the area. The affected tissue dies, injuring the heart. Symptoms include prolonged, intensive chest pain and a decrease in blood pressure that often causes shock.
Myocardial ischemia - Occurs when a part of the heart muscle does not receive enough oxygen.
Myocarditis – A rare condition in which the heart muscle becomes inflamed as a result of infection, toxic drug poisoning, or diseases like rheumatic fever, diphtheria, or tuberculosis.
Myxomatous degeneration - A connective tissue disorder that causes the heart valve tissue to weaken and lose elasticity.
Occluded artery - An artery in which the blood flow has been impaired by a blockage.
Pacemaker - A surgically implanted electronic device that helps regulate the heartbeat.
Palpitation - An uncomfortable feeling within the chest caused by an irregular heartbeat.
Paroxysmal supraventricular tachycardia (PSVT) – An occasional rapid heart rate (150-250 beats per minute) that is caused by events triggered in areas above the heart's lower chambers (the ventricles). See also supraventricular tachycardia (SVT).
Pericarditis - Inflammation of the outer membrane surrounding the heart. When pericarditis occurs, the amount of fluid between the two layers of the pericardium increases. This increased fluid presses on the heart and restricts its pumping action.
Plaque - A deposit of fatty (and other) substances in the inner lining of the artery wall characteristic of atherosclerosis.
Postural orthostatic tachycardia syndrome (POTS) - A disorder that causes an increased heart rate when a person stands upright.
Premature ventricular contraction (PVC) - An early or extra heartbeat that happens when the heart's lower chambers (the ventricles) contract too soon, out of sequence with the normal heartbeat.
Regurgitation - Backward flow of blood through a defective heart valve.
Rheumatic heart disease - A disease of the heart (mainly affecting the heart valves) caused by rheumatic fever.
Second-degree heart block - Impulses traveling through the heart's upper chambers (the atria) are delayed in the area between the upper and lower chambers (the AV node) and fail to make the ventricles beat at the right moment.
Septal defect - A hole in the wall of the heart separating the atria or in the wall of the heart separating the ventricles.
Silent ischemia - Episodes of cardiac ischemia that are not accompanied by chest pain.
Stenosis - The narrowing or constriction of an opening, such as a blood vessel or heart valve.
Stokes - Adams disease - Also called third-degree heart block; a condition that happens when the impulses that pace your heartbeat do not reach the lower chambers of your heart (the ventricles). To make up for this, the ventricles use their own "backup" pacemaker with its slower rate. This rhythm can cause severe dizziness or fainting and can lead to heart failure or death.
Supraventricular tachycardia (SVT) - A regular rapid heart rate (150-250 beats per minute) that is caused by events triggered in areas above the heart's lower chambers (the ventricles); see also paroxysmal supraventricular tachycardia (PSVT).
Syncope - A temporary, insufficient blood supply to the brain which causes a loss of consciousness. Usually caused by a serious arrhythmia.
Systolic blood pressure - The highest blood pressure measured in the arteries. It occurs when the heart contracts with each heartbeat.
Tachycardia - Accelerated beating of the heart. Paroxysmal tachycardia is a particular form of rapid heart action, occurring in seizures that may last from a few seconds to several days.
Tamponade - Also called cardiac tamponade. A condition in which the heart is compressed or constricted because of a large amount of fluid or blood in the space between the heart muscle and the sac that surrounds the heart (the pericardium).
Third-degree heart block - A serious condition also called Stokes-Adams disease; impulses from the heart's upper chambers (the atria) are completely blocked from reaching the heart's lower chambers (the ventricles). To make up for this, the ventricles use their own "backup" pacemaker with its slower rate.
Thrombosis - A blood clot that forms inside the blood vessel or cavity of the heart.
Transient ischemic attack (TIA) - A stroke-like event that lasts only for a short time and is caused by a temporarily blocked blood vessel.
Ventricular fibrillation - A condition in which the ventricles contract in a rapid, unsynchronized fashion. When fibrillation occurs, the ventricles cannot pump blood throughout the body.
Ventricular tachycardia - An arrhythmia (abnormal heartbeat) in the ventricle characterized by a very fast heartbeat.
Wolff-Parkinson-White syndrome - A condition in which an extra electrical pathway connects the atria (two upper chambers) and the ventricles (two lower chambers). It may cause a rapid heartbeat.