Marquette General Heart Institute
Heart Terms a-c
Abdominal aorta - The portion of the largest artery on the body that passes through the general area of the stomach in the body.
Ablation - Elimination or removal.
ACE (angiotensin-converting enzyme) inhibitor - A drug that lowers blood pressure by interfering with the breakdown of a protein-like substance involved in blood pressure regulation.
Alveoli - Air sacs in the lungs where oxygen and carbon dioxide are exchanged.
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.
Angiography - An x-ray technique that uses dye injected into the arteries to study blood circulation through the vessels. The test allows physicians to measure obstruction to blood flow. Circulation through a coronary artery is not seriously reduced until the inside diameter of the vessel is more than 75% obstructed.
Angioplasty - A technique for treating diseased arteries by temporarily inflating a tiny balloon inside an artery, flattening the plaque against the blood vessel wall.
Anticoagulant - Any drug that keeps blood from clotting; a blood thinner.
Antihypertensive - Any drug or other therapy that lowers blood pressure.
Aorta - The largest artery in the body and the initial blood-supply vessel from the heart.
Aortic valve - The valve that regulates blood flow from the heart into the aorta.
Aphasia - The inability to speak, write or understand spoken or written language because of brain injury or disease.
Arrhythmia (or dysrhythmia) - An abnormal heartbeat.
Arterioles - Small, muscular branches of arteries. When they contract, they increase resistance to blood flow, and blood pressure in the arteries increases.
Artery - A vessel that carries oxygen-rich blood to the body.
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.
Ascending aorta - The first portion of the aorta, emerging from the heart's left ventricle.
Atherectomy - A non-surgical technique for treating diseased arteries with a device that cuts or shaves away obstructing plaque or material inside the artery.
Atherosclerosis - A disease process that leads to the accumulation of a waxy substance, called plaque, inside blood vessels.
Atria - The two upper or holding chambers of the heart.
Atrial septal defect - See septal defect.
Atrioventricular block - An interruption or disturbance of the electrical signal between the heart's atria (upper two chambers) and the ventricles (lower two chambers).
Atrioventricular (AV) node - A group of cells located between the atria (upper two chambers) and the ventricles (lower two chambers) that regulates the electrical current (heart rhythm) that passes through it to the ventricles.
Atrium - Either one of the heart's two upper chambers.
Beta blocker - An antihypertensive drug that limits the activity of epinephrine, a hormone that increases blood pressure.
Biopsy - The process by which a small sample of tissue is taken for examination.
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; they can also form inside an artery whose walls are damaged by atherosclerotic build-up and are the major cause of 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.
Brachytherapy - Delivers radiation directly to the tissues designated for treatment while sparing the surrounding normal tissues.
Bundle-branch block - A condition in which portions of the heart's conduction system are defective and unable to conduct the electrical signal normally, causing arrhythmias.
Calcium channel blocker (or calcium blocker) - A drug that lowers blood pressure by regulating calcium-related electrical activity in the heart.
Capillaries - Microscopically small blood vessels between arteries and veins that distribute oxygenated blood to the body's tissues.
Cardiac - Pertaining to the heart.
Cardiac arrest - The stopping of the heartbeat, usually because of interference with the electrical signal (often associated with coronary heart disease).
Cardiac catheterization - A procedure that involves inserting a fine, hollow tube (catheter) into an artery, usually in the groin area, and passing the tube into the heart. Often used in conjunction with angiography and other procedures, cardiac catheterization has become a prime tool for visualizing the heart and blood vessels and diagnosing and treating heart disease.
Cardiac enzymes - Complex substances capable of speeding up certain biochemical processes in the cardiac muscle. Abnormal levels of these enzymes signal heart attack.
Cardiac output - The amount of blood the heart pumps through the circulatory system in one minute.
Cardiology - The study of the heart and its function in health and disease.
Cardiovascular (CV) - Pertaining to the heart and blood vessels.
Cardiopulmonary bypass - The process by which a machine is used to do the work of the heart and lungs so the heart can be stopped during surgery.
Cardioversion - A technique of applying an electrical shock to the chest in order to convert an abnormal heartbeat to a normal rhythm.
Cardiomyopathy - A disease of the heart muscle that leads to generalized deterioration of the muscle and its pumping ability.
Carotid artery - A major artery (right and left) in the neck supplying blood to the brain.
Cerebral embolism - A blood clot formed in one part of the body and then carried by the bloodstream to the brain, where it blocks an artery.
Cerebral hemorrhage - Bleeding within the brain resulting from a ruptured blood vessel, aneurysm, or a head injury.
Cerebral thrombosis - Formation of a blood clot in an artery that supplies part of the brain.
Cerebrovascular - Pertaining to the blood vessels of the brain.
Cerebrovascular accident (CVA) - Also called "brain attack", or stroke. A lack of blood supply to some part of the brain, resulting in injury and death of brain tissue
Cholesterol - An waxy substance that occurs naturally in the body, is also present in animal fats and in dairy products, and that is transported in the blood. Limited quantities are essential to the normal development of cell membranes. Excessive amounts of cholesterol however increase the risk of cardiovascular disease.
Cineangiography - The technique of taking moving pictures to show the movement of opaque dye through blood vessels, allowing physicians the ability to diagnose diseases of the heart and blood vessels.
Circulatory system - Pertaining to the heart, blood vessels and the circulation of blood.
Claudication - A tiredness or pain in the arms and legs caused by an inadequate supply of oxygen to the muscles, usually due to narrowed arteries.
Collateral circulation - Blood flow through small, nearby vessels in response to blockage of a main blood vessel.
Computed tomography (CT or CAT scan) - An x-ray technique that uses a computer to create cross-sectional images of the body.
Conduction system - Special muscle fibers that conduct electrical impulses throughout the muscle of the heart.
Congenital - Refers to conditions existing at birth.
Congenital heart defects - Malformation of the heart or of its major blood vessels present at birth.
Congestive heart failure - A condition in which the heart cannot pump all the blood returning to it, leading to a back up of blood in vessels and accumulation of fluid in body tissues, including the lungs.
Coronary arteries - Two arteries arising from the aorta that arch down over the top of the heart and divide into branches. They provide blood to the heart muscle.
Coronary artery bypass (CAB) - Surgical rerouting of blood around a diseased vessel that supplies the heart by grafting either a piece of vein from the leg or the artery from under the breastbone.
Coronary artery disease (CAD) - A narrowing of the inside diameter of arteries that supply the heart muscle with blood. The condition arises from accumulation of plaque and greatly increases a person's risk of having a heart attack.
Coronary heart disease - Disease of the heart caused by atherosclerotic narrowing of the coronary arteries likely to produce angina, (chest pain) or heart attack.
Coronary occlusion - An obstruction of one of the coronary arteries that hinders blood flow to some part of the heart muscle.
Coronary thrombosis - Formation of a clot in one of the arteries that carry blood to the heart muscle. Also called coronary occlusion.
Cyanosis - Blueness of skin caused by insufficient oxygen in the blood.
Deep vein thrombosis - A blood clot in the deep vein in the calf.
Defibrillator - An electronic device that helps reestablish normal electrical and contraction rhythms in a malfunctioning heart.
Diabetes (diabetes mellitus) - A disease in which the body doesn't produce or properly use insulin. Insulin is needed to convert sugar and starch into the energy needed in daily life.
Diastolic blood pressure - The lowest blood pressure measured in the arteries, it occurs when the heart muscle is relaxed between beats.
Diuretic - A drug that lowers blood pressure by stimulating fluid loss; promotes urine production.
Doppler ultrasound - A technology that uses sound waves to assess blood flow within the heart and blood vessels and to identify leaking valves.
Dyspnea - Shortness of breath.
Echocardiography - A method of studying the heart's structure and function by analyzing sound waves bounced off the heart and recorded by an electronic sensor placed on the chest. A computer processes the information to produce a one-, two- or three-dimensional moving picture that shows how the heart and heart valves are functioning.
Edema - Swelling caused by fluid accumulation in body tissues.
Ejection fraction - A measurement of blood that is pumped out of a filled ventricle. The normal rate is 50 percent or more.
Electrocardiogram (ECG or EKG) - A test in which several electronic sensors are placed on the body to monitor electrical activity associated with the heartbeat.
Electroencephalogram (EEG) - A graphic record of the electrical impulses produced by the brain.
Electrophysiological study (EPS) - A test that uses cardiac catheterization to study patients who have arrhythmias (abnormal heartbeats). An electrical current stimulates the heart in an attempt to cause an arrhythmia, which is then immediately treated with medication. EPS is used primarily to identify the origin of arrhythmias and to test the effectiveness of drugs used to treat abnormal heart rhythms.
Embolus - Also called embolism; a blood clot that forms in the blood vessel in one part of the body and travels to another part.
Endarterectomy - Surgical removal of plaque deposits or blood clots in an artery.
Endocardium - The smooth membrane covering the inside surfaces of the heart.
Endothelium - The smooth inner lining of many body structures, including the heart (endocardium) and blood vessels.
Endocarditis - A bacterial infection of the heart's inner lining.
Enlarged heart - A state in which the heart is larger than normal due to heredity, long-term heavy exercise, sustained alcohol abuse, or diseases and disorders such as obesity, high blood pressure, and coronary artery disease.
Enzyme - A complex chemical capable of speeding up specific biochemical processes in the body.
Epicardium - The thin membrane covering the outside surface of the heart muscle.
Estrogen - A female hormone produced by the ovaries that may protect women against heart disease. Estrogen is not produced after menopause.
Exercise stress test - A fairly common test for diagnosing coronary artery disease, especially in patients who have symptoms of heart disease. The test helps physicians assess blood flow through coronary arteries in response to exercise, usually walking at varied speeds and for various lengths of time on a treadmill. A stress test may include use of electrocardiography, echocardiography, and injected radioactive substances. Also called exercise test, stress test or treadmill test.
Familial hypercholesterolemia - A genetic predisposition to dangerously high cholesterol levels.
Fatty acids (fats) - Substances that occur in several forms in foods; different fatty acids have different effects on lipid profiles.
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.
Flutter - The rapid, ineffective contractions of any heart chamber. A flutter is considered to be more coordinated than fibrillation.
Gated blood pool scan - An x-ray analysis of how blood pools in the heart during rest and exercise. The test makes use of a radioactive substance injected into the blood to tag or label red cells. The test provides an estimate of the heart's overall ability to pump and its ability to compensate for one or more blocked arteries. Also called MUGA, for multi-unit gated analysis.
Heart attack - Death of, or damage to, part of the heart muscle due to an insufficient blood supply.
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-lung machine - An apparatus that oxygenates and pumps blood to the body during open heart surgery.
Heredity - The genetic transmission of a particular quality or trait from parent to offspring.
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."
Holter monitor - A portable device for recording heartbeats over a period of 24 hours or more.
Hypertension - High blood pressure.
Hypertrophic obstructive cardiomyopathy (HOCM) - An overgrown heart muscle that creates a bulge into the ventricle and impedes blood flow.
Hypoglycemia - Low levels of glucose in the blood.
Hypotension - Abnormally low blood pressure.
Hypoxia - Less than normal content of oxygen in the organs and tissues of the body.
Immunosuppressive medications - Any drug that suppresses the body's immune system. These medications are used to minimize the chances that the body will reject a newly transplanted organ such as a heart.
Impedance plethysmography - A noninvasive diagnostic test used to evaluate blood flow through the leg.
Infarct - The area of heart tissue permanently damaged by an inadequate supply of oxygen.
Inferior vena cava - The large vein returning blood from the legs and abdomen to the heart.
Inotropic medications - Any drug that increases the strength of the heart's contraction.
Intravascular echocardiography - A marriage of echocardiography and cardiac catheterization. A miniature echo device on the tip of a catheter is used to generate images inside the heart and blood vessels.
Ischemia - Decreased blood flow to an organ, usually due to constriction or obstruction of an artery.
Ischemic heart disease - Also called coronary artery disease and coronary heart disease, this term is applied to heart ailments caused by narrowing of the coronary arteries, and therefore characterized by a decreased blood supply to the heart.
Jugular veins - The veins that carry blood back from the head to the heart.
Lesion - An injury or wound. An atherosclerotic lesion is an area of an artery affected by plaque formation.
Lipid - A fatty substance insoluble in blood.
Lipoprotein - A lipid surrounded by a protein; the protein makes the lipid soluble in blood.
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."
Lumen - The hollow area within a tube, such as a blood vessel.
Magnetic resonance imaging (MRI) - A technique that produces images of body structures by measuring the response of certain elements (such as hydrogen) in the body to a magnetic field. When stimulated by radio waves, the elements emit distinctive signals in a magnetic field. MRI can produce detailed pictures of the body tissues or organs without the need to inject a dye.
Mitral valve - The structure that controls blood flow between the heart's left atrium (upper chamber) and left ventricle (lower chamber).
Mitral valve prolapse - A condition that occurs when the leaflets of the mitral valve between the left atrium (upper chamber) and left ventricle (lower chamber) bulge into the ventricle and permit backflow of blood into the atrium. The condition is often associated with progressive mitral regurgitation.
Monounsaturated fats - A type of fat found in many foods but predominantly in avocados and canola, olive and peanut oil. Monounsaturated fat tends to lower LDL (the bad) cholesterol levels. Some studies suggest that it may do so without also lowering HDL (the good) cholesterol levels.
Mortality - The total number of deaths from a given disease in a population during an interval of time, usually a year.
Murmur - The sound of blood flow 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 - 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, permanently damaging the heart. Symptoms include prolonged, pressure, tightness or pain in the chest, pain radiating to the shoulders, arms, neck or jaw; shortness of breath; light headedness, fainting ,sweating, extreme fatigue.
Myocardial ischemia - Deficient blood flow to an area of the heart muscle.
Myocardium - The muscular wall of the heart. It contracts to pump blood out of the heart and then relaxes as the heart refills with returning blood.
Nitroglycerin - A drug that helps relax and dilate arteries, allowing blood and oxygen to flow to the heart muscle, often used to treat chest pain (angina).
Necrosis - Referring to the death of tissue within a certain area.
Noninvasive procedures - Any diagnostic or treatment procedure in which no instrument enters the body.
Obesity - The condition of being significantly overweight. It is usually applied to a condition of 30 percent or more over ideal body weight. Obesity puts a strain on the heart and can increase the chance of developing high blood pressure and diabetes.
Occluded artery - An artery in which the blood flow has been impaired by a blockage.
Open heart surgery - An operation in which the chest and heart are opened surgically while the bloodstream is diverted through a heart-lung (cardiopulmonary perfusion) machine.
Pacemaker - A surgically implanted electronic device that helps regulate the heartbeat.
Palpitation - An uncomfortable sensation within the chest caused by an irregular heartbeat.
Patent ductus arteriosus - A congenital defect in which the opening between the aorta and the pulmonary artery does not close after birth.
Percutaneous transluminal coronary angioplasty (PTCA) - See angioplasty.
Pericarditis - Inflammation of the outer membrane surrounding the heart. Rheumatic fever, tuberculosis, and many other agents are its possible causes.
Pericardiocentesis - A diagnostic procedure using a needle to withdraw fluid from the sac or membrane surrounding the heart (pericardium).
Pericardium - The outer fibrous sac that surrounds the heart.
Plaque - A deposit of fatty (and other) substances in the inner lining of the artery wall; it is characteristic of atherosclerosis.
Platelets - One of the three types of cells found in blood; they aid in the clotting of the blood.
Polyunsaturated fat - The major fat constituent in most vegetable oils including corn, safflower, sunflower, and soybean. These oils are liquid at room temperature. Polyunsaturated fat actually tends to lower LDL cholesterol levels but may also reduce HDL cholesterol levels as well.
Positron emission tomography (PET) - A test that uses positron emitting substances to assess information about the metabolism of elements that can be used to indicate whether heart muscle is alive and functioning. A ring of radiosensitive detectors positioned around the chest reconstructs a two- or three-dimensional image of the heart.
Prevalence - The total number of cases of a given disease that exist in a population at a specific time.
Pulmonary - Referring to the lungs and respiratory system.
Pulmonary valve - The heart valve between the right ventricle and the pulmonary artery. It controls blood flow from the heart into the lungs.
Pulmonary vein - The blood vessel that carries newly oxygenated blood from the lungs back to the left atrium of the heart.
Ventriculography - A diagnostic test used to determine the size and shape of the heart's pumping chambers (the ventricles).
Regurgitation - Backward flow of blood through a defective heart valve.
Renal - Pertaining to the kidneys.
Rheumatic fever - A disease, usually occurring in childhood, that may follow a streptococcal infection. Symptoms may include fever, sore or swollen joints, skin rash, involuntary muscle twitching, and development of nodules under the skin. If the infection involves the heart, scars may form on heart valves, and the heart's outer lining may be damaged.
Risk factor - An element or condition involving a certain hazard or danger. When referring to heart and blood vessels, a risk factor is associated with an increased chance of developing cardiovascular disease, including heart attack, high blood pressure and/or stroke.
Rubella - Commonly known as German measles.
Saturated fat - Type of fat found in foods of animal origin and a few of vegetable origin; they are usually solid at room temperature. Abundant in meat and dairy products, saturated fat tends to increase LDL cholesterol levels, and it raises the risk of heart disease and certain types of cancer.
Septal defect - A hole in the wall of the heart separating the atria or in the wall of the heart separating the ventricles.
Septum - The muscular wall dividing a chamber on the left side of the heart from the chamber on the right.
Shock - A condition in which body function is impaired because the volume of fluid circulating through the body is insufficient to maintain normal metabolism. This may be caused by blood loss or by a disturbance in the function of the circulatory system.
Shunt - A connector that allows blood to flow between two locations.
Sick sinus syndrome - The failure of the sinus node to regulate the heart's rhythm.
Silent ischemia - Episodes of cardiac ischemia that are not accompanied by chest pain.
Sinus (SA) node - The "natural" pacemaker of the heart. The node is a group of specialized cells in the top of the right atrium which produces the electrical impulses that travel down to eventually reach the ventricular muscle, causing the heart to contract.
Sodium - A mineral essential to life found in nearly all plant and animal tissue. Table salt (sodium chloride) is nearly half sodium.
Sphygmomanometer - An instrument used to measure blood pressure.
Stent - A device made of expandable, metal mesh that is placed (by using a balloon catheter) at the site of a narrowing artery. The stent is then expanded and left in place to keep the artery open.
Stenosis - The narrowing or constriction of an opening, such as a blood vessel or heart valve.
Stethoscope - An instrument for listening to sounds within the body.
Streptococcal infection ("strep" infection) - An infection, usually in the throat, resulting from the presence of streptococcus bacteria.
Streptokinase - A clot-dissolving drug used to treat heart attack patients.
Sternum - The breastbone.
Stress - Bodily or mental tension resulting from physical, chemical or emotional factors. Stress can refer to physical exertion as well as mental anxiety.
Stroke - A sudden disruption of blood flow to the brain, either by a clot or a leak in a blood vessel.
Subarachnoid hemorrhage - Bleeding from a blood vessel on the surface of the brain into the space between the brain and the skull.
Sudden death - Death that occurs unexpectedly and instantaneously or shortly after the onset of symptoms. The most common underlying reason for patients dying suddenly is cardiovascular disease, in particular coronary heart disease.
Superior vena cava - The large vein that returns blood from the head and arms to the heart.
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, that may last from a few seconds to several days.
Tachypnea - Rapid breathing.
Thallium-201 stress test - An x-ray study that follows the path of radioactive potassium carried by the blood into heart muscle. Damaged or dead muscle can be defined, as can the extent of narrowing in an artery.
Thrombolysis - The breaking up of a blood clot.
Thrombosis - A blood clot that forms inside the blood vessel or cavity of the heart.
Thrombolytic therapy - A drug that dissolves blood clots.
Thrombus - A blood clot.
Tissue plasminogen activator (TPA) - A clot-dissolving drug used to treat heart attack and stroke patients.
Trans fat - Created when hydrogen is forced through an ordinary vegetable oil (hydrogenation), converting some polyunsaturates to monounsaturates, and some monounsaturates to saturates. Trans fat, like saturated fat, tends to raise LDL cholesterol levels, and, unlike saturated fat, trans fat also lowers HDL cholesterol levels at the same time.
Transesophageal echocardiography - A diagnostic test that analyzes sound waves bounced off the heart. The sound waves are sent through a tube-like device inserted in the mouth and passed down the esophagus (food pipe), positioned near the heart.
Transient ischemic attack (TIA) - A temporary, stroke-like event that lasts for only a short time and is caused by a temporarily blocked blood vessel.
Transplantation - Replacing a defective organ with one from a donor.
Tricuspid valve - The structure that controls blood flow from the heart's right atrium (upper chamber) into the right ventricle (lower chamber).
Triglyceride - The most common fatty substance found in the blood; normally stored as an energy source in fat tissue. High triglyceride levels may thicken the blood and make a person more susceptible to clot formation. High triglyceride levels tend to accompany high cholesterol levels and other risk factors for heart disease such as obesity.
Ultrasound - High-frequency sound vibrations, not audible to the human ear, used in medical diagnosis.
Valvuloplasty - Reshaping of a heart valve with surgical or catheter techniques.
Varicose vein - Any vein that is abnormally dilated.
Vascular - Pertaining to the blood vessels.
Vasodilators - Any medication that dilates (widens) the arteries.
Vasopressors - Any medication that elevates blood pressure.
Vein - Any one of a series of blood vessels of the vascular system that carries blood from various parts of the body back to the heart; returns oxygen-depleted blood to the heart.
Ventricle (right and left) - One of the two lower chambers of the heart.
Ventriculography - A diagnostic test used to determine the size, wall motion and pumping ability of the heart's pumping chambers (the ventricles).
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.
Vertigo - A feeling of dizziness or spinning.
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.
X-ray - Form of radiation used to create a picture of internal body structures on film.