Glossary of cardiovascular terminology

Glossary of Cardiovascular Terminology

Abdomen - The area of the body between the bottom of the ribs and the top of the thighs.
Abdominal aorta - The portion of the aorta in the abdomen.
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.
Acetylcholine - A type of chemical (called a neurotransmitter) that transmits messages among nerve
cells and muscle cells.
Alveoli - Air sacs in the lungs where oxygen and carbon dioxide are exchanged.
Amiodarone (Cordarone, Pacerone) - A kind of medicine (called an antiarrhythmic), which is used to
treat irregular heart rhythms such as atrial fibrillation and ventricular tachycardia. It works by regulating
nerve impulses in your heart. Amiodarone is mainly given to patients who have not responded to other
antiarrhythmic medicines.
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 makes use of a dye injected into the coronary arteries to study
blood circulation through the vessels. The test allows physicians to measure the degrees of
obstruction to blood flow. Circulation through an artery is not seriously reduced until the inside
diameter of the vessel is more than 75% obstructed.
Angioplasty - A nonsurgical technique for treating diseased arteries by temporarily inflating a tiny
balloon inside an artery.
Annulus - The ring around a heart valve where the valve leaflet merges with the heart muscle.
Antiarrhythmics - Medicines that are used to treat patients who have irregular heart rhythms.
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.
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. The most common symptoms are heart palpitations, fainting or loss of
consciousness (syncope), and, sometimes, sudden death.
Arteriography - A test that is combined with cardiac catheterization to visualize an artery or the
arterial system after injection of a contrast dye.
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.
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.
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 rotating device that cuts
or shaves away obstructing 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 flutter - A type of arrhythmia where 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 septal defect - See septal defect.
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
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.
Autoregulation - When blood flow to an organ stays the same although pressure changes in the
artery that delivers blood to that organ may have changed.
Bacteria - Germs that can lead to disease.
Bacterial endocarditis - A bacterial infection of the lining of the heart's chambers (called the
endocardium) or the heart's valves.
Balloon catheter - A long tube-like device with a small balloon on the end that can be threaded
through an artery. Used in angioplasty or valvuloplasty.
Balloon valvuloplasty - A procedure to repair a heart valve that is not working properly. A balloon-
tipped catheter is threaded through an artery and into the heart. The balloon is inflated to open and
separate any narrowed or stiffened flaps (called leaflets) of a valve. The catheter and deflated balloon
are removed after the procedure.
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.
Blalock-Taussig procedure - Palliative shunt between the subclavian and pulmonary arteries used to
increase the supply of oxygenated blood in
"blue" babies (see below).
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 can cause 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.
"Blue babies" - Babies who have a blue tinge to their skin (cyanosis) resulting from insufficient
oxygen in the arterial blood. This condition often
indicates a heart defect.
Bradycardia - Abnormally slow heartbeat.
Bruit - A sound made in the blood vessels that is a result of turbulence, perhaps due to a buildup of
plaque or damage to the vessels.
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.
Bypass - Surgery that can improve blood flow to the heart (or other organs and tissues) by providing a
new route, or "bypass," around a section of clogged or diseased artery.
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.
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.
Cardiopulmonary resuscitation (CPR) - An emergency measure that can maintain a person's
breathing and heartbeat. The person who performs CPR actually helps the patient's circulatory system
by breathing into the patient's mouth to give them oxygen and by giving chest compressions to
circulate the patient's blood.
Cardiovascular (CV) - Pertaining to the heart and blood vessels. The circulatory system of the heart
and blood vessels is the cardiovascular system.
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 - Also called cerebral vascular accident, apoplexy or stroke. An impeded
blood supply to some part of the brain, resulting in injury to brain tissue
Cerebrovascular occlusion - The obstruction or closing of a blood vessel in the brain.
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 quantities are essential to the normal development of cell
membranes.
Cineangiography - The technique of taking moving pictures to show the passage of an opaque dye
through blood vessels, which allows physicians 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.
Commissurotomy - A procedure used to widen the opening of a heart valve that has been narrowed
by scar tissue. First developed to correct rheumatic heart disease.
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
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 pectoris or heart attack; a general term.
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.
Cryoablation - The removal of tissue using an instrument called a cold probe.
Cyanosis - Blueness of skin caused by insufficient oxygen in the blood.
Cyanotic heart disease - A birth defect of the heart that causes oxygen-depleted (blue) blood to
circulate to the body without first passing through the lungs
Death rate (age-adjusted) - A death rate that has been standardized for age so different populations
can be compared or the same population can be compared over time.
Deep vein thrombosis - A blood clot in the deep vein in the calf.
Defibrillator - An electronic device that helps reestablish normal 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.
Digitalis - A drug made from the leaves of the foxglove plant. Digitalis is used to treat congestive heart
failure (CHF) and heart rhythm problems (arrhythmias). Digitalis can increase blood flow throughout
the body and reduce swelling in the hands and ankles.
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, which is the large
vessel that carries blood from the heart to other parts of the body.
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.
Dysarthria - The imperfect articulation of speech resulting from muscular problems caused by
damage to the brain or nervous system.
Dyspnea - A 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 test that can detect and record the brain's electrical activity. The
test is done by pasting metal disks, called electrodes, to the scalp.
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 effort to
provoke an arrhythmia, which is 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 of the heart. The innermost lining 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 (endothelium).
Enlarged heart - A state in which the heart is larger than normal due to heredity, long-term heavy
exercise, 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.
Estrogen (or hormone) replacement therapy (ERT or HRT) - Hormones that some women may
take to offset the effects of 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.
First-degree heart block - 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.
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.
Genetic testing - Blood tests that study a person's genes to find out if he or she is at risk for certain
diseases that are passed down through family members.
Heart assist device - A mechanical device that is surgically implanted to ease the workload of the
heart.
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.
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, which are common in children and usually do not
require treatment.
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.
Homocysteine – An amino acid (one of the building blocks that makes up a protein) normally found in
small amounts in the blood. Too much homocysteine in the blood may promote the buildup of fatty
plaque in the arteries. For some people, high homocysteine levels are genetic. For others, it is
because they do not get enough of certain B vitamins in their diet (B-12, B-6, and folic acid). Most
people can keep their homocysteine levels in check by eating foods rich in B vitamins. Your doctor
may also recommend a vitamin supplement. (common misspelling: homocystine)
Hormones - Chemicals released into the bloodstream that control different functions in the body,
including metabolism, growth, sexual development, and responses to stress or illness.
Hypertension - High blood pressure.
Hypertrophic obstructive cardiomyopathy (HOCM) - An overgrown heart muscle that creates a
bulge into the ventricle and impedes blood flow.
Hypertrophy - Tissues or organs that have grown in size because of increased workload.
Hyperventilation - Rapid breathing usually caused by anxiety. Persons 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.
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.

Idiopathic - No known cause.
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.
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.
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.
Ischemic stroke - A type of stroke that is caused by blockage in a blood vessel.
Jugular veins - The veins that carry blood back from the head to the heart.
Lesion - An injury or wound. An atherosclerotic lesion is an injury to an artery due to hardening of the
arteries.
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 the heart and other 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 heart and its various structures without the need to
inject a dye.
Mitral stenosis - A narrowing of the mitral valve, which controls blood flow from the heart's upper left
chamber (the left atrium) to its lower left chamber (the left ventricle). May result from an inherited
(congenital) problem or from rheumatic fever.
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.
Mitral valve regurgitation - Failure of the mitral valve to close properly, causing blood to flow back
into the heart's upper left chamber (the left atrium) instead of moving forward into the lower left
chamber (the left ventricle).
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 cholesterol levels, and some studies
suggest that it may do so without also lowering HDL cholesterol levels.
Mortality - The total number of deaths from a given disease in a population during an interval of time,
usually a year.
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 - 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 - Deficient blood flow to part of the heart muscle.
Myocarditis – A rare condition where the heart muscle becomes inflamed as a result of infection, toxic
drug poisoning, or diseases like rheumatic fever, diphtheria, or tuberculosis.
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.
Myxomatous degeneration - A connective tissue disorder that causes the heart valve tissue to
weaken and lose elasticity.
Nitroglycerin - A drug that helps relax and dilate arteries, often used to treat cardiac 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.
Pancreas - The organ behind the stomach that helps control blood sugar levels.
Pancreatitis - Swelling (inflammation) of the pancreas.
Paralysis - Loss of the ability to move muscles and to feel in part of the body or the whole body.
Paralysis may be temporary or permanent.
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.
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.
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 embolism - A condition in which a blood clot that has formed elsewhere in the body
travels to the lungs.
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.
Radionuclide imaging - A test in which a harmless radioactive substance is injected into the
bloodstream to show information about blood flow through the arteries. Damaged or dead heart
muscle can often be identified, as can serious narrowing in an artery.
Radionuclide studies - Any of the diagnostic tests in which a small amount of radioactive material is
injected into the bloodstream. The material makes it possible for a special camera to take pictures of
the heart.
Radionuclide 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.
Revascularization - A procedure to restore blood flow to the tissues. Coronary artery bypass surgery
is an example of a revascularization procedure.
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.
Rheumatic heart disease - A disease of the heart (mainly affecting the heart's valves) caused by
rheumatic fever.
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 stroke.
Rubella - Commonly known as German measles.
Saccular aneurysm - A round aneurysm that bulges out from an artery. Involves only part of the
circumference (outside wall) of the artery.
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 may raise the risk of certain types of cancer.
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.
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.
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. Stokes-Adams disease is very serious and can lead to heart
failure or death.

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, occurring in seizures 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.
Third-degree heart block - Also called Stokes-Adams attack; 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.
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 - Intravenous or intraarterial drugs used to dissolve blood clots in an artery.
Thrombus - A blood clot.
Thyroid - A gland located in the front of the neck, just below the voice box.
Tissue plasminogen activator (TPA) - A clot-dissolving drug used to treat heart attack 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.
Transcatheter intervention - Any of the non-invasive procedures usually performed in the cardiac
catheterization laboratory. Angioplasty is an example of a transcatheter intervention.
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), which ends near the heart. This technique is useful in studying patients
whose heart and vessels, for various reasons, are difficult to assess with standard echocardiography.
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.
Valve replacement - An operation to replace a heart valve that is either blocking normal blood flow or
causing blood to leak backward into the heart (regurgitation).
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.
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.

Source: http://www.stosswelle.in/whitepapers/11_Glossary_of_Cardiovascular_Terminology.pdf