Glossary of Terms

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

• 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.
• Anesthesiologist: A doctor who specializes in the science of anesthesia.
• Aneurysm: A sac-like protrusion from a blood vessel or the heart, resulting from a weakening of the vessel wall or heart muscle.
• Angina Pectoris: The medical term for chest pain due to coronary heart disease. A condition in which the heart muscle doesn’t receive enough blood, resulting in pain in the chest.
• Angiography: An X-ray examination of the blood vessels or chambers of the heart. It is made by tracing the course of a special fluid (called contrast or dye), visible by X-ray, that has been injected into the bloodstream. The X-ray pictures are called angiograms.
• Angiogram: The X-ray pictures that are made of the blood vessels or chambers of the heart by tracing the course of a special fluid (called a contrast medium or dye), that’s been injected into the bloodstream.
• 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.
• Antiphospholipid Syndrome: The antiphospholipid syndrome is a disorder of the immune system that is characterized by excessive clotting of blood and/or certain complications of pregnancy (premature miscarriages, unexplained fetal death, or premature birth) and the presence of antiphospholipid antibodies (cardiolipin or lupus anticoagulant antibodies) in the blood.
• Aorta: The large artery that receives blood from the left ventricle of the heart and distributes it to the body.
• Aortic Aneurysm: An aortic aneurysm is the dilation, bulging or ballooning out of part of the wall of the aorta, the artery through which blood flows out of the heart to the body.
• Aortic Regurgitation: The return of blood from the aorta into the left ventricle of the heart due to aortic insufficiency, incomplete closure of the aortic valve.
• Aortic valve: The heart valve between the left ventricle and the aorta. It has three flaps, or cusps.
• Arrhythmia: (Dysrhythmia) An abnormal rhythm of the heart.
• Artery: Any one of a series of vessels that carry blood from the heart to the various parts of the body.
• Arteritis: Inflammation of the arteries.
• Atresia: The absence of a normal opening.
• Atrium: Either one of the two upper chambers of the heart in which blood collects before being passed to the ventricles; also called auricle.
• Atherosclerosis: A medical condition in which fatty material collects along the walls of arteries. This fatty material thickens, hardens, and may eventually block the arteries.
• Atrial Fibrillation: Atrial fibrillation (AF) is the most common, abnormal rhythm of the heart.

B

• Bacterial endocarditis: A bacterial infection of the lining of the heart’s chambers (called the endocardium) or the heart’s valves.
• Balloon angioplasty: A procedure in which a balloon is inserted into a narrowed area of a blood vessel. When the balloon is inflated, the narrowed area is stretched open and then the balloon is removed. Also called balloon dilation angioplasty.
• Balloon valvuloplasty: A procedure in which a balloon is inserted into the opening of a narrowed heart valve. When the balloon is inflated, the valve is stretched open and then the balloon is removed.
• Blood pressure: The force or pressure exerted by the heart in pumping blood; pressure of the blood in the arteries.
• Bradycardia: Abnormally slow heartbeat.
• 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.

C

• Cardiac: Pertaining to the heart.
• Cardiac arrest: When the heart stops beating.
• Cardiac Catheterization: The process of examining the heart by introducing a thin tube (catheter) into a vein or artery and passing it into the heart.
• Cardiology: The study of the heart and its functions in health and disease.
• Cardiomyopathy: A disease of the heart muscle that leads to generalized deterioration of the muscle and its pumping ability.
• Cardiomyoplasty: A surgical procedure that involves detaching one end of a back muscle and attaching it to the heart. An electric stimulator causes the muscle to contract to pump blood from the heart.
• 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: Pertaining to the heart and blood vessels.
• Catheter: A thin tube inserted into a vein or artery.
• Catheterization: The process of examining the heart by inserting a thin tube (catheter) into a vein or artery and passing it into the heart. It is done to sample oxygen, measure pressure and make X-ray movies.
• Cerebrovascular Disease: The word “cerebrovascular” is made up of two parts “cerebro” which refers to the large part of the brain and “vascular” which means arteries and veins. Together, “cerebrovascular” refers to blood flow in your brain. The term cerebrovascular disease covers acute stroke and other diseases that may lead to stroke, like carotid stenosis and aneurysms.
• Chronic Obstructive Pulmonary Disease: Chronic obstructive pulmonary disease (COPD) is comprised primarily of two related diseases - chronic bronchitis and emphysema. In both diseases, there is chronic obstruction of the flow of air through the airways and out of the lungs, and the obstruction generally is permanent and progressive over time.
• Circulatory system: Pertaining to the heart, blood vessels and the circulation of blood.
• Congenital heart defect: Part of the heart or its major blood vessels that is not formed properly and does not work as it should at birth.
• Congestive heart failure: The inability of the heart to pump out all the blood that returns to it. This results in blood backing up in the veins that lead to the heart. Sometimes fluid builds up in various parts of the body.
• Coronary arteries: Two arteries arising from the aorta. The arteries arch down over the top of the heart, branch and provide blood to the working heart muscle.
• Coronary Artery Bypass Graft Surgery: Surgery to improve blood supply to the heart muscle. It’s most often performed when narrowed coronary arteries reduce the flow of oxygen-containing blood to the heart itself. Arteries or veins are taken from another part of the body to channel needed blood flow to the coronary arteries.
• Coronary Artery Disease: Conditions that cause the coronary arteries to narrow so blood flow to the heart muscle is reduced.
• Coronary Artery Spasm: A spasm (a sudden constriction) of one of the coronary arteries depriving the myocardium (the heart muscle) of blood and oxygen. This can cause chest pain referred to as variant (or Prinzmetal’s) angina.
• 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 a shortage of oxygen in the blood.

D

• 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 blood pressure inside the arteries when the heart muscle is relaxed.
• Diastolic heart failure: This occurs when the heart has a problem relaxing. The heart cannot properly fill with blood because the muscle has become stiff, losing its ability to relax. This form may lead to fluid accumulation, especially in the feet, ankles, and legs. Some patients may have lung congestion.
• 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.
• Digoxin: A drug often used in treating congestive heart failure. It makes the contraction of the heart muscle stronger, slows the rate of heart beats and helps remove extra fluid from body tissues. It’s also used sometimes to treat certain arrhythmias.
• 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 increases the rate that urine forms. It promotes the excretion of water and salts.
• Doppler: See Ultrasound.
• Dyspnea: Shortness of breath.
• Dysrhythmia: (Arrhythmia) An abnormal rhythm of the heart.

E

• Echocardiography: A diagnostic method in which pulses of sound are transmitted into the body. The echoes returning from the surfaces of the heart and other structures are plotted and recorded on electronic equipment.
• Edema: Abnormal fluid accumulation in body tissues.
• Endocarditis: An inflammation of the inner lining of the heart or heart valves.
• Endocardium: The smooth membrane covering the inside of the heart. The innermost lining of the heart.
• 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.

F

• 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 a-v block: A prolonged PR interval (greater than 200 msec) is called first-degree AV block. The PR interval of the surface ECG can be subdivided into intra-atrial, AV nodal and His-Purkinje system conduction times. An increase in the PR interval can result from conduction delays in any of these areas. However, first-degree AV block most commonly results from prolonged AV nodal conduction time, particularly in the presence of a narrow QRS complex. Drugs such as digitalis, beta-blockers and calcium channel blockers, which prolong AV nodal conduction, can also produce first-degree AV block. Atropine and isoproterenol can shorten the PR interval by enhancing AV nodal conduction. Less commonly, first-degree AV block can result from delay distal to the AV node such as the His-Purkinje system.
• 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.

H

• Heart attack: Death of, or damage to, part of the heart muscle due to an insufficient blood supply.
• Heart failure: Loss of blood-pumping ability by the heart.
• 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.
• High blood pressure: A chronic increase in blood pressure above the normal range. The increase persists over two or more measurements.
• Hypertension: Same as 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.
• Hypothermia: A procedure that lowers a patient's body temperature during surgery. It stops all blood circulation so the surgeon can safely repair the heart.

I

• 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.
• 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.

J

• J-curve: When the blood pressure or blood cholesterol levels of large groups of people are plotted on a graph against CVD mortality, it often results in a J-shaped curve. This curve shows that those with higher blood pressure and/or cholesterol levels, closer to the top of the curve, are more likely to die from CVD. The curve also shows that those at the lowest end of the curve (with very low blood pressure and/or low cholesterol levels) also have higher CVD mortality. This accounts for the J shape and is known as the J-curve phenomenon. Most evidence, however, indicates that the group at the bottom-left part of the curve (with very low blood pressure and low cholesterol levels) tends to be different from the general population in other ways. Those differences may contribute to the apparent increase in mortality. Treating high blood pressure or high cholesterol levels with drugs may have some side effects. However, treatment doesn’t result in the markedly low values linked with increased deaths from CVD. More studies are needed to find out the best treatment levels for different groups.

L

• Left ventricular assist device: A mechanical device used to increase the heart’s pumping ability.
• Long Q-T Syndrome: An inherited defect in the heart rhythm.

M

• Marfan Syndrome: Marfan syndrome is a heritable condition that affects the connective tissue.
• 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 heart valve between the left atrium and left ventricle. It has two flaps, or cusps.
• 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).
• Murmur: See Heart Murmur.
• Myocardial Infarction (Heart Attack): The damaging or death of an area of the heart muscle (myocardium) resulting from a reduced blood supply to that area.
• Myxomatous degeneration: A connective tissue disorder that causes the heart valve tissue to weaken and lose elasticity.

O

• Occluded artery: An artery in which the blood flow has been impaired by a blockage. Open-heart surgery: Surgery done on the opened heart while the bloodstream is diverted through a heart-lung machine.

P

• Pacemaker: The “natural” pacemaker of the heart is called the sinus node. The sinus node is a small mass of special cells in the top of the right atrium of the heart. It produces the electrical impulse that goes to the left atrium and travels down to reach the ventricular muscle. These impulses cause the heart to contract or “beat.” The term “artificial pacemaker” is applied to an electrical device that can be used to replace a defective natural pacemaker or conduction pathway. The artificial pacemaker controls the heart's beating and rhythm by emitting a series of electrical discharges.
• Palpitation: An uncomfortable sensation within the chest caused by an irregular heartbeat.
• Percutaneous Transluminal Angioplasty (PTA): A procedure sometimes used to dilate (widen) narrowed arteries. A catheter with a deflated balloon on its tip is passed into the narrowed artery segment, the balloon is inflated, and the narrowed segment is widened.
• Pericarditis: Inflammation of the outer membrane surrounding the heart. Rheumatic fever, tuberculosis, and many other agents are its possible causes.
• Peripheral Vascular Disease (PVD): Diseases of the blood vessels (arteries and veins) located outside the heart and brain.
• Plaque: Also called atheroma, this is a deposit of fatty (and other) substances in the inner lining of the artery wall characteristic of atherosclerosis.
• Premature Ventricular Contractions (PVCs): Premature heartbeats originating from the ventricles of the heart. PVCs are premature because they occur before the regular heartbeat.
• Pulmonary artery: The large artery that receives blood from the right ventricle and takes it to the lungs.
• Pulmonary congestion (or edema): Fluid accumulation in the lungs.
• Pulmonary (pulmonic) valve: The heart valve between the right ventricle and the pulmonary artery. It has three flaps, or cusps.

R

• Raynaud’s Phenomenon (RP): a condition resulting in discoloration of the fingers and/or the toes after exposure to changes in temperature (cold or hot) or emotional events. Skin discoloration occurs because an abnormal spasm of the blood vessels causes a diminished blood supply to the local tissues.
• Regurgitation: The abnormal backward flowing of blood through a valve of the heart.
• 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.
• Ross Procedure: Pulmonary autograft (patient’s own pulmonary valve to aortic valve position) & Pulmonary homograft (cryopreserved human pulmonic valve to pulmonic valve position).
• Rubella: Commonly known as German measles.

S

• Saccular aneurysm: A round aneurysm that bulges out from an artery. Involves only part of the circumference (outside wall) of the artery.
• Septal defect: A hole in the wall of the heart separating the atria or in the wall of the heart separating the ventricles.
• Septum: One of the muscular walls dividing the two chambers on the left side of the heart from the two chambers on the right. The atrial septum separates the top chambers and the ventricular septum separates the bottom chambers.
• Silent Ischemia: Ischemia is a condition in which the blood flow (and thus oxygen) is restricted to a part of the body. Cardiac ischemia is the name for lack of blood flow and oxygen to the heart muscle. People who have ischemia without pain have silent ischemia. They may have a heart attack with no prior warning. People with angina also may have undiagnosed episodes of silent ischemia. An exercise test or a 24-hour portable monitor of the electrocardiogram (Holter monitor) are two tests often used to diagnose this problem.  Other tests also may be used.
• Stenosis: The narrowing or constriction of an opening (such as a 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. Stokes-Adams disease is very serious and can lead to heart failure or death.
• Streptokinase: A clot-dissolving drug used to treat heart attack patients.
• Stroke: A sudden disruption of blood flow to the brain, either by a clot or a leak in a blood vessel.
• Sudden Cardiac Death: During sudden cardiac death, the electrical system to the heart suddenly becomes irregular. The ventricles may flutter or quiver (ventricular fibrillation), and blood is not delivered to the body.
• Systolic blood pressure: Pressure inside the arteries when the heart contracts with each beat.
• Systolic heart failure: This occurs when the heart’s ability to contract decreases. The heart cannot pump with enough force to push a sufficient amount of blood into the circulation. Blood coming into the heart from the lungs may back up and cause fluid to leak into the lungs, a condition known as pulmonary congestion.

T

• 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.
• Tricuspid valve: The heart valve between the right atrium and right ventricle. It has three flaps, or cusps.

U

• Ultrasound: High-frequency sound vibrations, that a human ear cannot hear, used in medical diagnosis. In pediatric cardiology the ultrasound test includes both echocardiography (shows a picture of the heart) and the Doppler test (analyzes blood flow).

V

• Valve: An opening, covered by membrane flaps, between two chambers of the heart or between a chamber of the heart and a blood vessel. When it's closed, no blood normally passes through.
• Vascular: Pertaining to the blood vessels.
• Vein: Any one of a series of vessels that carry blood from various parts of the body back to the heart.
• Ventricle: One of the two lower chambers of the heart.
• Ventricular Fibrillation: An abnormal irregular heart rhythm whereby there are very rapid uncoordinated fluttering contractions of the lower chambers (ventricles) of the heart. Ventricular fibrillation disrupts the synchrony between the heartbeat and the pulse beat. Ventricular fibrillation is most commonly associated with heart attacks or scarring of the heart muscle from previous heart attack. It is life threatening.

W

• 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.