Glossary of heart disease

American Heart Month

• Alpha Blockers — A group of drugs used to lower blood pressure.

• Aneurysm — An abnormal widening or ballooning-out of the wall of an artery, a vein or theheart due to weakening of the wall by disease, injury or an abnormality present at birth. Somecommon locations for aneurysms include the aorta (the major artery leading away from theheart), brain (cerebral aneurysm), leg, intestine and splenic artery.

• Angioplasty — A medical procedure in which a balloon is used to open narrowed or blockedblood vessels of the heart (coronary arteries). A catheter with a deflated balloon on its tip ispassed into the narrowed artery segment, the balloon is inflated and the narrowed segmentwidened. Then the balloon is deflated and the catheter is removed.

• Antiarrhythmic Medication — A group of drugs that helps control and slow heart rate. Thetype of arrhythmia you have determines which medication will be prescribed.

• Anticoagulant (Blood Thinners) — A group of drugs that decrease the ability of the blood toclot, or coagulate. They are sometimes called blood thinners, although they do not actually thinthe blood.

• Antihypertensive Drugs — A group of drugs commonly prescribed to help lower bloodpressure when appropriate diet and regular physical activity alone have not succeeded. Theyinclude diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blocker(ARBs), vasodilators, alpha-blockers, beta-blockers, calcium channel blockers and centralalpha-agonists. Many patients with high blood pressure may require more than one drug toachieve control. Some of these drugs may also be prescribed for heart failure and arrhythmiapatients.

• Antiplatelet Agents — A group of drugs used to keep blood clots from forming by preventingblood platelets from sticking together.

• Aorta — The large artery that receives blood from the heart’s left ventricle and distributes it tothe body.

• Aortic Valve — The heart valve between the left ventricle and the aorta. It has three flaps(cusps).

• Arrhythmia (Dysrhythmia) — An abnormal heartrhythm caused by a disruption of the normalfunctioning of the heart’s electrical conduction system.

• Arteriography — A testing procedure in which a dye visible to X-rays is injected into thebloodstream. Then X-ray pictures are taken and studied to see if the arteries are damaged,narrowed or blocked. Arteriography is done during cardiac catheterization. (Also known asAngiocardiography, Angiogram and Angiography.)

• Arterioles — Small, muscular branches of arteries. When they contract, they increaseresistance to blood flow, and blood pressure in the arteries increases.  

• Arteriosclerosis — Commonly called hardening of the arteries, this includes a variety ofconditions that cause artery walls to thicken and lose elasticity. Arteriosclerosis can occurbecause of fatty deposits on the inner lining of arteries (atherosclerosis), calcification of the wallof the arteries, or thickening of the muscular wall of the arteries from chronically elevated bloodpressure. It also is associated with aging. Atherosclerosis is a form of arteriosclerosis

• Artery — One of a series of vessels that carry oxygenated blood from the heart to the variousparts of the body. Their thick elastic walls expand as blood flows through the arteries.

• Artificial Heart — A prosthetic device that is implanted into the body to replace the originalbiological heart.

• Atrial Fibrillation — A disorder of heart rate and rhythm in which the heart’s two small, upperchambers (atria) quiver rapidly and empty blood into the heart’s lower chambers (ventricles) in adisorganized manner instead of beating effectively. Blood that isn’t pumped completely out ofthe atria when the heart beats may pool and clot.

• Atrial Flutter — Very rapid beating of the heart's upper chambers (atria). This rhythm occursmost often in people with heart diseases such as pericarditis, coronary artery disease andcardiomyopathy.

• Beta-Blockers (Beta-Adrenergic Blocking Agents) — A class of drugs that slow theheartbeat, lessen the force with which the heart muscle contracts and reduce blood vesselcontraction in the heart, brain and throughout the body.

• Blood Clot — A jelly-like mass of blood tissue formed by clotting (coagulating) factors in theblood.

• Blood Pressure — The force or pressure exerted by the heart against the walls of the arteries.When the arterioles (smaller arteries) constrict (narrow), the blood must flow through a smaller“pipe” and the pressure rises. High blood pressure can result, adding to the workload of theheart and arteries. Optimal blood pressure is less than 120/80 mm Hg. High blood pressure, orhypertension, is a condition in which blood pressure levels are above the normal range. Bloodpressures of 120–139 / 80–89 mm Hg are considered prehypertension. Blood pressure isconsidered high if it is 140/90 mm Hg or higher. High blood pressure increases the risk for heartattack, angina, stroke, kidney failure and peripheral artery disease (PAD). High blood pressuremay also increase the risk of developing fatty deposit in arteries (atherosclerosis). The risk ofheart failure also increases due to the increased workload that high blood pressure places onthe heart.

• Blood Vessels — Hollow tubes that carry blood from the heart and lungs to every cell in thebody and back to the heart and lungs. These tubes are flexible and respond to circumstancesand hormonal changes in the body by dilating, (becoming larger) or constricting (becomingsmaller). Arteries are blood vessels that carry blood from the heart. Veins are blood vessels thatcarry blood back to the heart.

• Blood Vessel Dilators (Vasodilators) — Drugs that cause the blood vessels (especially thearterioles) to expand by relaxing their muscular walls. This lowers blood pressure and reducesthe heart's workload. ACE inhibitors and nitroglycerine are examples of vasodilators.

• Bradycardia — Slowness of the heart rate (less than 60 beats per minute). Bradycardia can bepresent in otherwise normal individuals and is common in well-trained athletes and in most  persons during deep sleep. It can also be related to heart metabolic abnormalities and heartdisease. If it presents no symptoms, it usually doesn’t require treatment. However, withsymptoms such as fainting (syncope), chest pain (angina), heart failure and high bloodpressure, it should be treated.

• Bypass Surgery — (See Coronary Artery Bypass Graft)

• C-Reactive Protein (CRP) Test — Blood test that measures the concentration of C-reactiveprotein (CRP), a plasma protein known as acute phase protein, that rises in the blood withinflammation from certain conditions. Since inflammation is believed to play a role in thedevelopment of coronary artery disease (atherosclerosis), a highly sensitive assay (hs-CRP)test may be added to the screening battery of cholesterol and other lipid tests to help detectpeople at risk for a heart attack.

• Calcium Channel Blockers (Calcium Antagonists) — A class of drugs that blocks themovement of calcium into the heart and blood vessel muscle cells. This causes the muscles torelax, lowering blood pressure, slowing the heart rate and decreasing oxygen demands of theheart. These medications lower blood pressure in patients with hypertension, but have littleeffect on normal blood pressure. Since they decrease the heart’s pumping strength, slow theheart rate and relax blood vessels, they are also used to treat other heart conditions, such aschest pain (angina) and abnormal heart rhythms (arrhythmias).

• Capillaries — Microscopically small blood vessels between arteries and veins that distributeoxygenated blood to the body’s tissues.

• Cardiac — Pertaining to the heart.

• Cardiac Arrest — Cardiac arrest is the sudden, abrupt loss of heart function. It's also calledsudden cardiac arrest or unexpected cardiac arrest. Most cardiac arrests occur when theelectrical impulses in the diseased heart become rapid (ventricular tachycardia) or chaotic(ventricular fibrillation) or both. This irregular heart rhythm (arrhythmia) causes the heart tosuddenly stop beating. Cardiac arrest can be reversed if it's treated within a few minutes withcardiopulmonary resuscitation (CPR) and an electric shock (defibrillation) to the heart to restorea normal heartbeat. Sudden cardiac death (SCD) occurs within minutes after symptoms appearunless cardiac arrest is reversed. The term "massive heart attack" is often wrongly used in themedia to describe sudden death from cardiac arrest. The term "heart attack" refers to death ofheart muscle tissue due to the loss of blood supply, not necessarily resulting in a cardiac arrestor the death of the heart attack victim. A heart attack may cause cardiac arrest and suddencardiac death, but the terms aren't synonymous. (See Sudden Cardiac Death)

• Cardiac Catheterization — The process of examining the heart by guiding a thin tube(catheter) into a vein or artery and passing it into the heart and into the coronary arteries.Coronary Arteriography (angiography) and angioplasty (PTCA, Balloon Angioplasty) are doneduring a cardiac catheterization.

• Cardiac Computed Tomography (CT Scan), Computerized Axial Tomographic Scan (CAT

• scan) — An X-ray imaging technique that uses a computer to produce tomographic, or cross-sectional, images of the chest (including the heart and great vessels) or the brain. It’s used todiagnosis and evaluate heart diseases such as aortic diseases, cardiac masses and pericardialdisease and to define the areas in the brain affected by stroke.  

• Cardiac Enzymes — Enzymes in the body that are sometimes called heart damage markersbecause they are released into the bloodstream when heart muscle cells are damaged. Therehas been an increased emphasis on developing blood tests that detect injury in the heartmuscle as early as possible. These blood tests can confirm or refute suspicions raised early inthe evaluation of heart disease, especially in the emergency setting.

• Cardiac Positron Emission Tomography (PET) — A non-invasive nuclear imaging techniquethat uses tomographic (cross-sectional) images and radioactive tracers to study and quantifyhow the heart tissue works. Cardiac PET scans are used to diagnose coronary artery disease(CAD) and can be used to identify injured but viable (living) myocardium (heart muscle).

• Cardiac (Cardiovascular) Rehabilitation — Cardiovascular rehabilitation is a medicallysupervised program to help heart patients recover quickly and improve their overall physical andmental functioning. The goal is to reduce the risk of another cardiac event or to keep an existingheart condition from getting worse. Cardiac rehabilitation programs allow patients to havemedically supervised counseling, exercise, vocational guidance and assistance with making thelifestyle changes necessary for a healthy heart. Research has shown that patients whoparticipate in rehabilitation programs have a higher survival rate and a better quality of life.

• Cardiac Resynchronization (Biventricular Pacing) — A treatment for heart failure that uses athree-lead biventricular pacemaker implanted in the chest. The pacemaker sends tiny electricalimpulses to the heart muscle to coordinate (resynchronize) the pumping of the chambers of theheart, improving the heart’s pumping efficiency. Both ventricles are paced to contract at thesame time. This can reduce the symptoms of heart failure.

• Cardiologist — A doctor who diagnoses and treats heart problems.

• Cardiology — The study of the heart and its functions in health and disease.

• Cardiomyopathy (Myocarditis) — A serious disease affecting the heart. It involves aninflammation and reduced function in heart muscle. There are multiple causes including viralinfections. In cardiomyopathy, the heart muscle becomes inflamed and weakened, causingsymptoms of heart failure, which can mimic a heart attack. Cardiomyopathy can be classified asprimary or secondary. Primary cardiomyopathy can't be attributed to a specific cause, such ashigh blood pressure, heart valve disease, artery diseases or congenital heart defects.Secondary cardiomyopathy is due to specific causes. It's often associated with diseasesinvolving other organs as well as the heart. There are three main types of cardiomyopathy —dilated, hypertrophic and restrictive. Treatment includes evaluation and treating the underlyingcause.

• Cardiomyoplasty — An investigational procedure in which skeletal muscles are taken from apatient's back or abdomen and wrapped around an ailing heart. This added muscle, aided byongoing stimulation from a device similar to a pacemaker, may boost the heart's pumpingmotion. This procedure is experimental, and is performed in limited numbers. Recent researchsuggests that it may not be as effective as originally hoped.

• Cardiopulmonary Bypass (Heart/Lung Machine) — A procedure to circulate and oxygenatethe blood while surgery is performed on the heart. It involves diverting blood from the heart andlungs through a heart/lung machine and the return of oxygenated blood to the aorta.

• Cardiopulmonary Resuscitation (CPR) — An emergency lifesaving procedure that isperformed when a person’s own breathing or heartbeat have stopped. It uses a combination of chest compressions and mouth-to-mouth breathing (rescue breathing). The chest compressionskeep oxygenated blood circulating and the breathing provides oxygen to the lungs until aneffective heartbeat and breathing can be restored or the patient can be put on advanced cardiaclife support.

• Cardiovascular — Pertaining to the heart and blood vessels. (“Cardio” means heart; “vascular”means blood vessels.) The circulatory system of the heart and blood vessels is thecardiovascular system.

• Cardioversion — Delivering an electrical shock to a person’s heart to rapidly restore anabnormal heart rhythm (arrhythmia) back to normal. External cardioversion is performed with adefibrillator, either in an emergency situation or as a scheduled treatment for arrhythmia.Internal cardioversion is delivered by a device similar to a pacemaker, called an implantablecardioverter defibrillator (ICD). ICDs are used to treat arrhythmias in the lower heart chamber(ventricle) such as ventricular tachyarrhythmia or fibrillation. These arrhythmias can causesudden cardiac death (SCD) because of the dangerously fast heart rate. Internal cardioversionis also used to treat arrhythmias of the upper heart chamber (atrium) in some cases. The deviceused in this case is called an atrial defibrillator.

• Carotid Artery — One type of major artery in the neck carrying blood from the heart to thebrain. The other type is vertebral artery.

• Carotid Artery Disease (Carotid Artery Stenosis) — A carotid artery narrowed by a buildup ofplaque. Carotid artery disease, a type of atherosclerosis, is a major risk factor for ischemicstroke.

• Carotid Artery Stent — The carotid artery is a major artery in the neck that carries blood to thebrain. Carotid angioplasty is used to open a narrowed artery to allow more blood to flow throughto help prevent stroke. Stents are used to prop an artery open after angioplasty. A stent is a wiremesh tube that is collapsed into a small diameter, put over a balloon catheter and moved intothe area of blockage. When the balloon is inflated, the stent expands and locks in place, holdingthe artery open. The stent stays in the artery permanently to prop it open and improve bloodflow.

• Carotid Phonoangiography — A test using a sensitive microphone placed on the neck, veryclose to the carotid artery. It records sounds and detects blockages, such as those caused bycarotid artery disease.

• Catheterization — (See Cardiac Catheterization)

• Central Agonists (Central Alpha-Agonists) — Drugs that lower heart rate and reduce bloodpressure. They work by preventing the brain from sending signals to the nervous system tospeed up the heart rate and narrow the blood vessels. As a result, the heart doesn’t pump ashard and blood flows more easily through blood vessels.

• Cerebral — Pertaining to the brain.

• Cerebral Angiography — A procedure used most frequently to confirm cases of stroke, tumor,bulging of the artery walls (aneurysm), a clot or narrowing of the arteries and to evaluate thearteries of the head and neck before surgery. It is used to get more exact information aftersomething abnormal, such as bleeding within the brain, has been detected by an MRI or CTscan of the head. The arteries are not normally seen in an X-ray, so a contrast dye is injected into one or more arteries to make them visible. For the cerebral angiography, the dye is injectedinto one or both of the carotid, or vertebral, arteries in the neck (leading to the brain). (Alsoknown as carotid angiography, vertebral angiogram and head angiography.)

• Cerebral Aneurysm (Brain Aneurysm) — A brain aneurysm is a ballooning-out of the wall ofan artery in the brain. Often this wall is weakened by disease, injury or an abnormality presentat birth. Aneurysms are often caused or made worse by high blood pressure. They aren't alwayslife-threatening, but serious consequences, such as stroke, can result if one bursts in the brain.This is called a hemorrhagic (or bleeding) stroke. When a blood vessel on the brain's surfaceruptures and bleeds into the space between the brain and the skull (but not into the brain itself),it's called a subarachnoid hemorrhage. When an artery in the brain bursts, flooding thesurrounding tissue with blood, it's called a cerebral hemorrhage.

• Cerebral Embolism — An embolism occurs when foreign material, such as a broken-off pieceof plaque or a blood clot travels through the bloodstream and becomes lodged in a blood vesselblocking the flow of blood. When an embolism blocks the flow of blood to the brain, it is called acerebral embolism. A type of stroke.

• Cerebral Hemorrhage — Bleeding within the brain, resulting from a ruptured aneurysm or ahead injury. It results in a hemorrhagic stroke.

• Cerebral Thrombosis — Formation of a blood clot inside a blood vessel or artery that suppliespart of the brain, blocking the flow of blood. A type of stroke.

• Cerebrovascular — Pertaining to the brain and its major blood vessels.

• Cerebrovascular Accident (CVA) — The medical term for a stroke (apoplexy). Strokes can beeither ischemic (loss of blood supply) or hemorrhagic (bleeding into the brain). (See Stroke)

• Cholesterol — A soft, waxy substance found among the lipids (fats) in the bloodstream and inall the body's cells. It's an important part of a healthy body because it's used to form cellmembranes, some hormones and is needed for other functions. Cholesterol and other fats can'tdissolve in the blood. They have to be transported to and from the cells by special carrierscalled lipoproteins. There are several kinds, but the most important are low-density lipoprotein(LDL or “bad”) and high-density lipoprotein (HDL or “good”). (See LDL Cholesterol]] and HDL cholesterol.

• Cholesterol-Lowering Drugs — Cholesterol-lowering drugs reduce LDL (“bad”) cholesterol,increase HDL (“good”) cholesterol and reduce triglycerides (a blood fat). Several classes ofdrugs are used to treat cholesterol including statins. People may be prescribed a “combination”therapy of drugs depending on their specific situations. Cholesterol-lowering drugs have beenproven to reduce risks for heart disease. Due to potential side effects, patients who are takingmost cholesterol-lowering drugs may need to have periodic liver function tests.

• Chronic Illness — An illness or condition that develops slowly and persists for a long time.Heart failure is almost always a chronic illness.

• Cineangiography — The technique of taking moving pictures to show how a dye visible by X-ray passes through blood vessels.

• Circulatory System — Pertaining to the heart, blood vessels and the blood’s circulation.  

• Closed-Heart Surgery — An operation on the heart (or more typically the great vessels)without the need for cardiopulmonary bypass. Examples of closed-heart surgery include repairsof coarctation of the aorta and patent ductus arteriosus.

• Congenital Heart Disease (CHD) — A broad term for a number of different abnormalitiespresent at birth (congenital) affecting the heart. Though present at birth, the effects of theseabnormalities may not be obvious immediately. In some cases, the defects may not be evidentfor years, may never cause any problems and are compatible with normal physical activity and anormal life span. Congenital heart disease is responsible for more deaths in the first year of lifethan any other birth defects. Many of these defects need to be followed carefully. Though someheal over time, others will require treatment. Congenital heart disease is often divided into twotypes: those with cyanosis (blue discoloration caused by a relative lack of oxygen) and thosewithout cyanosis.

• Congestive Heart Failure (Heart Failure) — An older term for heart failure. Because not allpatients with heart failure have problems with excess fluid, such as in the lungs or extremities,the term "heart failure" is preferred over "congestive heart failure." Heart failure is the inability ofthe heart to pump out all the blood that returns to it. This results in blood backing up in the veinsthat lead to the heart and sometimes in fluid accumulating in various parts of the body. (See also heart failure.

• Coronary Arteries — Two arteries arising from the aorta that arch down over the top of theheart, branch and provide blood to the heart muscle.

• Coronary Artery Disease (CAD) — Conditions that cause narrowing of the coronary arteries,reducing blood flow to the heart muscle. A type of atherosclerosis. Severe cases can result inheart attack.

• Coronary Artery Bypass Graft (Bypass Surgery) — Surgery that reroutes (bypasses) bloodaround clogged coronary arteries and improves the supply of blood and oxygen to the heartmuscle. It’s sometimes called open-heart surgery or CABG (for coronary artery bypass graft) or“cabbage.”

• Coronary Heart Disease (CHD) — Disease of the heart caused by atherosclerotic narrowing ofthe coronary arteries likely to produce chest pain (angina pectoris) or heart attack.

• Coronary Occlusion (or Coronary Thrombosis) — An obstruction of a coronary artery thathinders blood flow to some part of the heart muscle. A cause of heart attack.

• Defibrillation — The use of an electrical device (defibrillator) to give an electric shock to theheart to help restore a normal heartbeat. It is used for dangerous arrhythmias, such asventricular tachycardia or ventricular fibrillation, and in cardiac arrest.

• Defibrillator — A device that delivers “pacing” or an electric shock to the heart when anabnormal rhythm (arrhythmia) is detected. A defibrillator may be external or internal. Externaldefibrillators use pads that are placed on the chest to deliver the electric shock. Internaldefibrillators (implantable cardioverter defibrillators or ICDs) look similar to a pacemaker, butthey continuously monitor the heart rhythm to detect overly rapid arrhythmias such asventricular tachycardia or ventricular fibrillation. The ICD corrects the heart rhythm by deliveringprecisely calibrated and timed electrical shocks to restore a normal heartbeat when one of thesedangerous arrhythmias has occurred.  

• Diastolic Blood Pressure — The lowest blood pressure measured in the arteries that occurswhen the heart muscle relaxes between beats. In a typical blood pressure reading, such as120/78, the lower number is diastolic blood pressure. It is measured in millimeters of mercury(mmHg).

• Digital Cardiac Angiography (DCA), Digital Subtraction Angiography (DSA) — A modifiedform of computer imaging that records pictures of the major blood vessels to the heart or brain.It shows blockages, how severe they are and what can be done about them.

• Digitalis (also Digoxin, Digitoxin) — A drug that strengthens the contraction of the heartmuscle and slows the heart rate. It's often used to treat congestive heart failure and is also usedto treat certain heart rhythm abnormalities (arrhythmias).

• Diuretic (or Water Pill) — A drug that increases the rate at which urine forms by promoting theexcretion of water and salts. This helps to relieve the heart's workload and also decreases thebuildup of fluid in the lungs and other parts of the body, such as the ankles and legs. Differentdiuretics remove fluid at varied rates and through different methods. They are used to treat highblood pressure, congestive heart failure and some congenital heart defects.

• Doppler Ultrasound — A test that uses high-frequency sound waves to detect blockages in anartery and to evaluate blood flow.

• Echocardiography (or Echocardiogram) — A diagnostic method in which a hand-held deviceis placed on the chest and high-frequency sound waves (ultrasound) are used to produceimages of the heart’s size, structure and motion. An “echo” provides valuable information aboutthe health of the heart and helps gather information about abnormal rhythms (arrhythmias).

• Edema — Swelling due to an abnormally large amount of fluid in the intracellular body tissuespaces. Edema is common in the legs, ankles and lungs of people with heart failure.

• Electrocardiogram (or Electrocardiography, ECG or EKG) — A quick, painless test thatrecords the electrical activity of the heart. It may be taken at rest or during exercise. It is thestandard clinical tool for diagnosing arrhythmias (abnormal rhythms) and to check if the heart isgetting enough blood or if areas of the heart are abnormally thick. Small patches calledelectrodes are placed on different parts of the body. Different tracings of the heart's electricalactivity can be made and permanently recorded on paper or in a computer. Three major wavesof electric signals appear on the ECG. Each one shows a different part of the heartbeat. The Pwave records the electrical activity of the atria. The QRS wave records the electrical activity ofthe ventricles, and the T wave records the heart's return to the resting state. Doctors study theshape and size of the waves, the time between waves and the rate and regularity of beating.This tells a lot about the heart and its rhythm.

• Exercise Stress Test (Treadmill Test) — A diagnostic test in which a person walks on atreadmill or pedals a stationary bicycle while hooked up to equipment that monitors the heart.The test monitors heart rate, breathing, blood pressure, electrical activity (on anelectrocardiogram) and the person’s level of tiredness. It shows if the heart’s blood supply issufficient and if the heart rhythm is normal. (Also known as Exercise Test, Exercise CardiacStress Test or ECST.)

• Fibrillation — Fast, uncoordinated contractions of individual heart muscle fibers. The heartchamber involved can’t contract all at once and pumps blood ineffectively, if at all.  

• HDL Cholesterol — Often called “good” cholesterolbecause a high level of it seems to protect against heart attack and other cardiovascularconditions. People with a low HDL cholesterol level (less than 40 mg/dL in men, less than 50mg/dL in women) have a higher risk of heart disease. A low level of HDL cholesterol also mayraise stroke risk.

• Heart Attack (Myocardial Infarction) — Death of or damage to part of the heart muscle due toan insufficient blood supply. Heart attacks occur when one of the coronary arteries that supplyblood to the heart muscle is blocked. Blockage is usually caused from a buildup of plaque(deposits of fat-like substances) due to atherosclerosis. If a plaque deposit tears or ruptures, ablood clot may form and block the artery, causing a heart attack. Heart attack is also called acoronary thrombosis or coronary occlusion.

• Heart Murmur — An abnormal sound in the heart caused by defective heart valves or holes inthe heart walls. The sound is made by blood circulating through the heart's chambers andvalves, or through blood vessels near the heart. A person can be born with a heart murmur or itcan be caused by pregnancy, fever, thyrotoxicosis (a condition resulting from an overactivethyroid gland) or anemia.

• Heart Rate — The heart contracts (beats) as the electrical impulse moves through it. Thisnormally occurs 60 to 100 times a minute. The heart's upper chambers (atria) contract a split-second before the lower chambers (ventricles). This lets the atria empty their blood into theventricles before the ventricles contract.

• Heart Transplant — Surgery that replaces a damaged heart with a healthy heart taken from adonor who has been declared brain dead.

• Heart Valve — There are four valves in the heart. The valves control the direction of blood flowthrough the heart by opening and closing with each heartbeat. The valves permit the blood toflow in only one direction. The four valves are: tricuspid valve (between the right atrium and theright ventricle); pulmonary valve (between the right ventricle and the pulmonary artery; mitralvalve (between the left atrium and the left ventricle) and aortic valve (between the left ventricleand the aorta).

• Hypertension — Medical term for high blood pressure. (See High Blood Pressure.)

• LDL Cholesterol — Often called “bad” cholesterol, LDL cholesterolis the major cholesterol carrier in the blood. If too much LDL cholesterol circulates in the blood,it can slowly build up in the walls of the arteries that lead to the heart and brain. Together withother substances it can form plaque, a thick, hard deposit that can clog those arteries. Thiscondition is known as atherosclerosis. A high level of LDL cholesterol (160 mg/dL and above)reflects an increased risk of heart disease. An optimal level is less than 100 mg/dL. Levels from100–129 mg/dL are near or optimal. Levels from 130–159 mg/dL are borderline high, which alsoincreases risk for heart disease or stroke. LDL cholesterol level may be a better indicator of riskfor a heart attack or stroke than total cholesterol, and drug therapy is initiated based on the levelof LDL cholesterol. The lower the LDL cholesterol, the lower the risk for heart disease or stroke.For people with heart disease, the LDL cholesterol should be less than 100 mg/dL. For thosewith severe heart disease, the doctor may suggest that the LDL cholesterol level be less than 70mg/dL.

• Lipid — A fatty substance insoluble in blood. Cholesterol, cholesterol compounds, andtriglycerides are all lipids. They are transported in the blood as part of large molecules calledlipoproteins. Abnormalities in lipids can contribute to heart disease. It is recommended that all  adults age 20 or older have a fasting lipoprotein profile (total cholesterol, LDL cholesterol, HDLcholesterol and triglyceride) done every 5 years. People at higher risk for cardiovasculardisease (CVD) or who are on cholesterol-lowering medication will need to have their cholesterolchecked more often

• Low-Density Lipoprotein (LDL) — A type of protein that transports “bad” cholesterol in theblood. It’s the major cholesterol carrier in the blood. (See LDL Cholesterol.)

• Mitral Valve — The valve located between the heart's left upper chamber (atrium) and left lowerchamber (ventricle). It has two flaps (cusps) that open and close, similar to a double door.

• Myocardium — The muscular center layer of the heart between the outer layer (epicardium)and the inner layer (endocardium). The myocardium is responsible for the heart’s pumpingaction and contracts to pump blood out of the heart and then relaxes as the heart refills withreturning blood. The myocardium is the layer that has the largest oxygen needs and is mostaffected by decreased blood flow (ischemia).

• Nitroglycerin — A drug (a vasodilator) that relaxes (dilates) blood vessels and increases thesupply of blood and oxygen to the heart while reducing its workload. “Nitro” is used to treatacute chest pain (angina), in which case it is prescribed as quick-dissolving pills to be placedunder the tongue when needed. It can also be prescribed as a routine medication, in which caseit is available as slower-release pills, creams or patches. When the blood vessels dilate, bloodflow to the tissues increases. This can relieve chest pain.

• Pacemaker — The “natural” pacemaker of the heart is called the sinus node. It’s a small groupof specialized cells in the top of the heart’s right chamber (atrium). It produces the electricalimpulses that travel down to the heart’s lower chambers (ventricles), causing the heart tocontract. An “artificial pacemaker” is an electrical device that can substitute for a defectivenatural pacemaker or conduction pathway. An artificial pacemaker regulates the speed andrhythm of the heartbeat. Usually these devices are used for hearts that beat too slowly.Pacemakers run on batteries and usually last many years.

• Palpitations — The sensation of the heart beating rapidly or irregularly.

• Pulmonary Edema — Fluid buildup (edema) in the lungs usually due to mitral stenosis or leftventricular failure. Symptoms of pulmonary edema include difficulty breathing, coughing upblood, excessive sweating, anxiety and pale skin.

• Thrombosis — The formation or presence of a blood clot (thrombus) inside a blood vessel orchamber of the heart

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