Here is a glossary of terms and definitions related to heart disease:
Ablation: Permanent disruption of a problematic electric pathway in the heart with a heated catheter.
Advance Directive (living will): A document written in "good" health which informs your family and health care providers of your wishes for extended medical treatment in times of emergency. It also is used to determine what measures to take in the event of impending death.
Aerobic Exercise: Exercise which raises the heart rate and can both improve your functional ability and, in some cases, reduce symptoms of heart disease. It is repetitive in nature and involves the large muscle groups. Examples are walking, swimming, and cycling.
Ambulatory Monitors: Small portable electrocardiograph machines that are able to record the heart's rhythm. Each type of monitor has unique features related to length of recording time and ability to send the recordings over the phone. Types of ambulatory monitors include: Holter Monitor, Loop Recorder, Event Monitor, and Transtelephonic transmitter.
Anemia: A condition characterized by a deficiency of red blood cells. Anemia reduces the amount of oxygen available to the body.
Aneurysm: A sac formed by the bulging of a blood vessel wall or heart tissue. When aneurysms grow too large, they can rupture and the bleeding can be life threatening. Aneurysms that have grown too large should be repaired.
Angina (also called angina pectoris): Discomfort or pressure, usually in the chest, caused by a temporarily inadequate blood supply to the heart muscle, usually due to atherosclerosis, or blockages in the arteries. Discomfort may also be felt in the neck, jaw, or arms.
Angiogenesis: The spontaneous or drug-induced growth of new blood vessels. The growth of these vessels may help to alleviate coronary artery disease by rerouting blood flow around clogged arteries.
Angiogram (cardiac catheterization): A test used to diagnose heart disease. During the procedure, a catheter is inserted into an artery, usually in the leg or wrist, and contrast dye is injected into the arteries and heart. X-rays of the arteries and heart are taken.
Angioplasty: An invasive procedure, during which a specially designed balloon catheter with a small balloon tip is guided to the point of narrowing in the artery. Once in place, the balloon is inflated to compress the fatty matter and plaque into the artery wall and stretch the artery open to increase blood flow to the heart.
Angiotensin-Converting Enzyme Inhibitors (ACE inhibitors): A group of drugs used to treat high blood pressure and heart failure. ACE inhibitors block a specific enzyme (ACE or angiotensin-converting enzyme) that retains salt in the kidney and can cause heart and blood pressure problems. ACE inhibitors have been shown to decrease the risk of dying from a heart attack and to improve heart function.
Angiotensin II Receptor Blockers (ARBs): A group of drugs used to treat high blood pressure.
Annulus: A ring of tough fibrous tissue that is attached to and supports the leaflets of the heart valve.
Anomalous Coronary Artery: The normal anatomy for the coronary arteries involves their origin from the aorta at each of two separate sites. People can be born with the origin of a coronary artery that comes from an abnormal site, and this can lead to problems of coronary ischemia, which can subsequently lead to a heart attack. Not all coronary anomalies need surgery, but some do, and the specific operation depends on which of the many varieties of coronary anomalies is present.
Antiarrhythmic: A drug that is used to treat abnormal heart rhythms.
Anticoagulant ("blood thinner"): A medication that prevents blood from clotting; used for people at risk for atrial fibrillation, stroke, or blood clots.
Antihypertensive: A medication used to treat high blood pressure.
Aorta: Large artery leaving the heart. All blood pumped out of the left ventricle travels through the aorta on its way to other parts of the body.
Aortic Insufficiency : Aortic insufficiency refers specifically to the aortic valve, which is the valve the blood passes through as it leaves the heart and enters the aorta. When blood leaks back through the valve, it is known as aortic insufficiency. Small amounts of aortic insufficiency may be inconsequential, but larger amounts require repair or replacement of the aortic valve.
Aortic Valve: The aortic valve is the last valve through which the blood passes before it enters the aorta or main blood vessel of the body. The valve's role is to prevent blood from leaking back into the left ventricle from the aorta after it has been ejected from the heart.
Aortic Valve Replacement: When the aortic valve is diseased, it can become either stenotic (too narrow) or insufficient (leaky). In such cases, the aortic valve may need to be replaced with either a prosthetic or human valve. There are other types of valves used such as from a pig or cow; the type of valve replacement depends on the person's case. Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure to replace an aortic valve that can't fully open because of stenosis.
Aortic Valve Homograft: When replacement of an aortic valve is necessary, it is possible to replace the valve with another human valve known as an aortic valve homograft. This operation requires a cardiopulmonary bypass machine.
Aortic Valve Repair: The aortic valve is the last valve in the heart through which the blood travels prior to circulating in the body. When this valve is leaking or too tight, a surgeon may be able to repair the valve rather than replace it.
Arrhythmia: An irregular heartbeat.
Arterial Grafting: In patients who require coronary artery bypass graft surgery, it is sometimes desirable to use arteries from other parts of the body to provide the bypass grafts. This is known as arterial grafting. The alternative is to use vein grafts for coronary bypass surgery.
Arteries: Blood vessels that carry blood away from the heart.
Atherectomy (Directional Coronary Atherectomy or DCA): This rare procedure is used to clean out clogged heart arteries. A DCA catheter has a hollow cylinder on the tip with an open window on one side and a balloon on the other. When the catheter is inserted into the narrowed artery, the balloon is inflated, pushing the window against the fatty matter clogging the vessel. A blade (cutter) within the cylinder rotates and shaves off any fat that has protruded into the window. The shavings are caught in a chamber within the catheter and removed. This process is repeated as needed to allow better blood flow.
Atherosclerosis ("hardening of the arteries"): The process whereby abnormal deposits of lipids, cholesterol, inflammatory cells, and plaque build-up lead to coronary artery disease and other cardiovascular problems.
Atria: The upper chambers of the heart. (Atrium refers to one chamber of the heart).
Atrial Fibrillation (AF): Atrial fibrillation is an irregular heart rhythm in which many impulses begin and spread through the atria. The resulting rhythm is disorganized, rapid, and irregular, and the atria are not able to fully empty their contents into the ventricles, which increases the risk for blood clotting.
Atrial Flutter: Atrial flutter is a regular heart rhythm in which many impulses begin and spread through the atria. The resulting rhythm is organized, but so rapid that the atria are not able to fully empty their contents into the ventricles.
Atrial Myxoma: A myxoma is a tumor of the heart. It resides in the atrial chamber and causes symptoms when its growth produces a tumor so large it obstructs blood flow through the heart chambers.
Atrial Septal Defect: An abnormal hole located in the walls between the two atria of the heart. Tiny defects called patent foramen ovale are present in up to 30% of people and are of no consequence except in unusual circumstances, but may be implicated in strokes. Moderate-size to larger-size defects should be corrected and may require heart surgery.
Atrioventricular (AV) Node: A group of special cells located near the center of the heart that helps to regulate the heart rhythm. Here, the electrical current slows for a moment before going on to the ventricles.
Atrium: The top chamber of the heart. There are two atria -- the left and the right, divided by a muscular wall, called the septum. The atrium contracts before the ventricle to allow optimal filling of the ventricle.
Balloon Angioplasty (Percutaneous Transluminal Coronary Angioplasty or PTCA): A procedure used to clean out clogged heart arteries. A specially designed balloon catheter with a small balloon tip is guided to the point of narrowing in the artery. Once in place, the balloon is inflated to compress the fatty matter and plaque into the artery wall and stretch the artery open to increase blood flow to the heart.
Batista Procedure: During this surgical procedure to treat heart failure, the surgeon cuts out a piece of the patient's enlarged left ventricular muscle. The intention is to reduce the size of the left ventricular cavity, improve left ventricular function, and reverse congestive heart failure. This procedure is not successful in the long term, but it has led to better surgical techniques to treat those with heart failure (see infarct exclusion surgery).
Beta-Blocker: A drug that slows heart rate, lowers blood pressure, controls angina, helps regulate arrhythmias, and protects patients with prior heart attacks from future heart attacks. It increases the time that the heart can fill with blood and therefore decreases the amount of work the heart needs to do.
Bicuspid Valve: A valve with two leaflets (cusps) instead of the normal three. Aortic bicuspid valves run in families and can lead to aortic stenosis at younger ages.
Biopsy: Removal and analysis of a tissue sample.
Blood Pressure: The force exerted in the arteries by blood as it circulates. It is divided into systolic (when the heart contracts) and diastolic (when the heart is filling) pressures.
Body Mass Index (BMI): A number that reflects body weight adjusted for height.
Bradycardia: A slow heart rate.
Bundle Branch: Part of the electrical pathway of the heart that delivers electrical impulses to the ventricles of the heart. The bundle divides or branches into a right bundle and a left bundle. The bundles take the impulse through the ventricles (bottom chambers) to cause them to contract.
Bundle Branch Block: Normally, the electrical impulse travels down both the right and left bundle branches at the same speed, and the ventricles contract at the same time. If there is a block in one of the branches, it's called a bundle branch block. A bundle branch block causes one ventricle to contract just after the other ventricle and may be a sign of heart damage.
Calcium-Channel Blocker: A drug that reduces spasms of the blood vessels, lowers blood pressure, and controls angina; acts by selectively blocking the uptake of calcium by the cells.
Capillaries: Tiny blood vessels connecting arteries to veins. These blood vessels carry oxygen and nutrients to individual cells throughout the body.
Carbohydrate: An organic compound, found in food substances such as sugar, cereal and other grain products, and fruits and vegetables, which provides fuel for the body.
Carbon Dioxide: A gas created during metabolism, when the cells use oxygen to burn fat and release energy. The lungs release carbon dioxide when you breathe out.
Cardiac Arrest: When the heart stops beating suddenly and respiration (breathing) and other body functions stop as a result.
Cardiac Catheterization (angiogram): A procedure used to diagnose heart disease. During the procedure, a catheter (inserted into an artery in your arm or leg) is guided to your heart, contrast dye is injected, and X-rays of the coronary arteries, heart chambers, and valves are taken. Its main function is to look for blockages in the arteries. This procedure also measures the pressures in the heart chambers to help diagnose the causes of heart failure and to see the significance of valve problems.
Cardiac Output: The amount of blood pumped by the heart each minute.
Cardiac Rehabilitation: A structured program of education, nutrition, exercise, and activity guided toward lifestyle modification, increasing functional capabilities, and peer support.
Cardiologist: Doctor specializing in the diagnosis and treatment of heart disease.
Cardiomyopathy: An abnormal heart condition in which the heart is dilated (poor pumping power and enlarged), restrictive (impaired ability of the heart to fill), or hypertrophic (a thickened heart).
Cardiopulmonary Resuscitation (CPR): A technique designed to temporarily circulate oxygenated blood through the body of a person whose heart has stopped. It involves assessing the airway; if necessary, breathing for the person by mouth-to-mouth resuscitation or placing a tube into the breathing tube (trachea) and administering oxygen; determining if the person is without a pulse; and if necessary, applying compression to the chest to circulate blood.
Cardiovascular: Relates to the heart and blood vessels.
Cardioversion: A procedure used to convert an irregular heart rhythm to a normal heart rhythm by applying electric shock or using certain medications.
Catheter: A slender, hollow, flexible tube.
Chest X-ray (CXR, chest film): A very small amount of radiation is used to produce an image of the structures of the chest (heart, lungs, and bones) on film.
Cholesterol: A fatty substance made by the body and found in some foods. Cholesterol is deposited in the arteries in coronary artery disease.
Chordae Tendinae: Thin chords that provide support to the tricuspid and mitral valves of the heart, helping them to open and shut properly.
Clubbing: An abnormality where the ends of the fingers and toes enlarge and the nails curve; often it is related to an inadequate oxygen-rich blood supply. However, it can be hereditary and completely normal. It is often seen with congenital heart defects, but is most often present because of other conditions such as severe lung disease.
Coarctation of the Aorta: A severe narrowing of the aorta, causing a decrease in blood flow to the lower part of the body. This narrowing is a congenital defect and can be corrected with surgery.
Collateral Blood Vessels: Small capillary-like branches of an artery that form over time in response to narrowed coronary arteries. The collaterals "bypass" the area of narrowing and help to restore blood flow. However, during times of increased exertion, the collaterals may not be able to supply enough oxygen-rich blood to the heart muscle.
Commissurotomy: A surgical or catheter procedure that helps to repair the damage caused by defective heart valves. In some patients, specifically those with rheumatic heart disease, this area of the heart (also called the commissures) can become scarred and the valve leaflets fail to open and allow blood to flow through easily. In this surgery, the commissures can be released or reopened.
Complex Carbohydrates: Starchy foods that are good sources of energy and nutrients, such as whole grain breads, rice, and pasta.
Congenital Heart Defects: Heart defects present at birth.
Congestive Heart Failure (CHF or heart failure): A condition where the heart muscle weakens and can't pump blood efficiently throughout the body. This is called systolic heart failure. Another type of congestive heart failure is due to lack of relaxation of the heart muscle causing fluid to be forced into the lungs, abdomen, and legs. This type is called diastolic heart failure.
Constrictive Pericarditis: The pericardium is the sac around the heart. In people with constrictive pericarditis, this sac becomes inflamed and scarred leading to shrinkage of the pericardium. This can prevent the heart from filling to its full extent.
Coronary Arteries: Network of blood vessels that branch off the aorta to supply the heart muscle with oxygen-rich blood. There are two main coronary arteries: the right and the left. The left splits into two arteries called the circumflex and the left anterior descending (LAD) arteries, thus, the heart is often considered to have three major coronary arteries.
Coronary Artery Disease (atherosclerosis): A build-up of fatty material in the wall of the coronary artery that causes narrowing of the artery.
Coronary Spasm: Repeated contractions and dilations of the coronary arteries, causing a lack of blood supply to the heart muscle. It may occur at rest and can even occur in people without significant coronary artery disease.
Cyanosis: A blue tint to the skin, indicating the body is not receiving enough oxygen-rich blood.
Defibrillator: A machine that is used to administer an electric shock to the heart in order to re-establish normal heart rhythm.
Diabetes: A condition in which the body does not produce or respond to insulin (a hormone produced by your body, which allows blood sugar or glucose into your body's cells for energy).
Diastolic Blood Pressure: The pressure of the blood in the arteries when the heart is filling. It is the lower of two blood pressure measurements (for example, 120/80, where 80 is the diastolic pressure).
Dilated Cardiomyopathy: A disease of the myocardium (heart muscle) that causes the heart cavity to become stretched and enlarged and the pumping capacity of the heart to be reduced.
Dilatation: The increase in the size of a blood vessel or heart chamber.
Dipyridamole Stress Test: If you are unable to exercise on a treadmill or stationary bicycle for a stress test, a medication, called dipyridamole (Persantine) can be used instead of exercise to dilate the arteries in order to assess the heart's blood flow and look for areas of blockages. Other drugs that are also utilized in stress tests now are adenosine (Adenocard) and Lexiscan.
Diuretic: A drug that enables the kidneys to rid the body of excess fluid. A diuretic may be referred to as a "water pill."
Dobutamine Stress Echocardiogram (Dobutamine echo): A procedure that involves infusing a medication (dobutamine) through an intravenous (IV) line while you are closely monitored. This drug stimulates your heart, allowing evaluation of heart and valve function at rest and with exertion when you are unable to exercise on a treadmill or stationary cycle.
Echocardiography is an imaging procedure that creates a graphic outline of the heart's movement, valves and chambers using high-frequency sound waves that come from a handheld wand placed on your chest.
Dyspnea: Difficulty breathing or shortness of breath.
Echocardiogram (echo): An imaging procedure that creates a moving picture outline of the heart's valves and chambers using high-frequency sound waves that come from a handheld wand placed on your chest or passed down your throat. Echo is often combined with Doppler ultrasound and color Doppler to evaluate blood flow across the heart's valves. Doppler senses the speed of sound and can pick up abnormal leakage or restriction of the valves.
ECMO(Extra corporeal Membrane Oxygenation): In people who are unable to provide oxygen for their own blood or enough blood circulation, they can be put on life support known as extra corporeal membrane oxygenation. The blood is withdrawn from a large vein in the body and passes through a pumping mechanism, and then through a device that puts oxygen into the blood and removes carbon dioxide from the blood. The blood is then returned to the body and circulated in such a way as to sustain life.
Edema: Swelling; the accumulation of fluids, usually in the hands, feet, legs, or abdomen.
Ejection Fraction (EF): The amount of blood pumped out of a ventricle during each heartbeat. The ejection fraction evaluates how well the heart is pumping.
Electrocardiogram (ECG, EKG): The EKG records on graph paper the electrical activity of the heart using small electrode patches attached to the skin.
Electrophysiology (EP) Study: An EP study is a test that evaluates the electrical activity within your heart. This test is used to help your doctor find out the cause of your rhythm disturbance and the best treatment for you. During the test, your doctor may safely reproduce your abnormal heart rhythm, then give you medications to see which one controls it best.
Embolus: A blood clot that moves through the bloodstream.
Endocarditis: An infection of the inner lining of the heart or its valves. It is usually caused by bacteria and is more likely to occur in people who have heart valve defects or have had heart surgery to treat valve disease.
Enhanced External Counterpulsation (EECP): A treatment for those with symptomatic coronary artery disease (also called refractory angina), who are not eligible for standard treatments of revascularization (such as heart bypass surgery.) During EECP, cuffs wrapped around the calves, thighs, and buttocks are inflated and deflated, gently but firmly compressing the blood vessels in the lower limbs, increasing blood flow to the heart. EECP may stimulate the openings or formation of collateral vessels to create a "natural bypass" around narrowed or blocked arteries.
Event Monitor (Loop recorder): A small recorder (monitor) is attached to electrodes on your chest. It is worn continuously for a period of time. If symptoms are felt, an event button can be depressed, and the heart's rhythm is recorded and saved in the recorder. The rhythm can be saved and transmitted over the phone line.
Exercise Stress Echocardiogram (Stress Echo): A procedure that combines echocardiography with exercise to evaluate the heart's function at rest and with exercise. It can evaluate the heart muscle to determine if it is receiving enough oxygen, as well as evaluate the function of the valves. Echocardiography is an imaging procedure that creates a picture of the heart's movement, valves, and chambers using high-frequency sound waves that come from a handheld wand placed on your chest. Echo is often combined with Doppler ultrasound and color Doppler to evaluate blood flow across the heart's valves.
Exercise Stress Test: A test used to provide information about how the heart responds to stress. It usually involves walking on a treadmill or pedaling a stationary bike at increasing levels of difficulty, while the electrocardiogram, heart rate, and blood pressure are monitored. If you are not able to do activity, medications may be used to "stress" the heart.
Fat: A high-energy fuel source.
Fiber: An indigestible carbohydrate found in foods such as fruits and vegetables; aids in digestion. It can also decrease cholesterol and stabilize sugar metabolism.
Fibrillation: Abnormally rapid, inefficient contractions of the atria or ventricles. Ventricular fibrillation is life-threatening.
Flutter: One form of rapid heartbeat.
Free Mammary Artery Graft: When the surgeon removes the mammary artery from its origin to use as a heart bypass graft.
Free Radical: A destructive fragment of oxygen produced as a by-product. Increased free radicals are thought to trigger atherosclerosis.
Glucose: Blood sugar.
Head Upright Tilt Test (HUT, tilt table test, head-up tilt test): A test used to determine the cause of fainting spells. The test involves being tilted at different angles for a period of time. Heart rhythm, blood pressure, and other measurements are evaluated with changes in position.
Heart Attack (myocardial infarction): A lack of blood supply to the heart that is usually caused by a blood clot in the coronary artery. This results in permanent damage to the heart muscle and the severity of damage varies from normal, mild, to severe.
Heart Block: Also called an arrhythmia, the electrical current is slowed between the atria and ventricles. In more severe cases, conduction is blocked completely and the atria and ventricles beat independently. This is when a pacemaker would be suggested.
Heart Failure (congestive heart failure, CHF): A progressive condition where the heart muscle weakens and cannot pump blood efficiently. Fluid accumulates in the lungs, ankles, or other parts of the body and is often associated with shortness of breath.
Heart Lung (Cardiopulmonary) Bypass Machine: A machine that oxygenates the blood and circulates it throughout the body during surgery.
Heart Surgery: Heart surgery is any surgery that involves the heart or heart valves.
Heart Valves: There are four valves in the heart: the tricuspid and the mitral valve, which lie between the atria and ventricles, and the pulmonic and aortic valves, which lie between the ventricles and the blood vessels leaving the heart. The heart valves help to maintain one-way blood flow through the heart.
Hemoglobin: A protein in red blood cells that transports oxygen and carbon dioxide and gives blood its red color.
Hibernating Myocardium: After a heart attack, some areas of heart muscle do not pump as they should. Some areas will have permanent damage. Other areas are able to return to their normal function if blood flow is returned to that area by medications or a procedure. Hibernating myocardium is a heart muscle that is ''stunned or in shock" and may possibly return to normal function.
High-Density Lipoprotein (HDL): Lipoprotein is a particle in the blood. HDL is known as "good" cholesterol because it deposits cholesterol in the liver, where it is excreted by the body, protecting the arteries from the negative effects of the LDL cholesterol. High HDL is thought to protect against coronary artery disease.
Holter Monitor: A small recorder (monitor) is attached to electrodes on your chest. It records the heart's rhythm continuously for 24-hours as you go about your normal activities. After the monitor is removed the heart's beats are counted and analyzed by a technician with the aid of a computer. Your doctor can learn if you are having irregular heartbeats, what kind they are, how long they last, as well as what may cause them.
Homocysteine: An amino acid in the body. High levels of homocysteine are a risk factor for coronary artery disease.
Hydrogenation: A process used to harden unsaturated liquid vegetable oils into saturated fats.
Hyperlipidemia: High levels of fat in the blood, such as cholesterol and triglycerides.
Hypertension: High blood pressure.
Hypertrophic Obstructive Cardiomyopathy (HOCM): See IHSS below.
Hypertrophy: An abnormal enlargement of an organ or thickening of its tissue. Ventricular hypertrophy is the name given to a thickened ventricle.
Hypotension: Low blood pressure.
Idiopathic: When the cause of a disease or process is not known.
IHSS: Idiopathic Hypertrophic Subaortic Stenosis is another term used synonymously with hypertrophic obstructive cardiomyopathy (HOCM). It is an inherited disease that causes thickening of the heart muscle and other changes to the heart that significantly impair its function. Although the disease is rare, IHSS is the single most common cause of sudden cardiac arrest in seemingly healthy young people.
Immunosuppressants: Drugs that are used to keep the body's immune system from rejecting a transplanted organ, such as the heart, or to slow down the destructive processes of autoimmune disease (where the body's immune system goes awry and kills normal cells and tissue.)
Implantable Cardioverter Defibrillator (ICD): A surgically inserted electronic device that constantly monitors your heart rate and rhythm. When it detects a very fast, abnormal heart rhythm, it delivers electrical energy to the heart muscle to help the heart to beat in a normal rhythm again.
Infarction: Tissue death due to lack of oxygen-rich blood.
Inotrope Medication: A medication used to strengthen the heart's contractions and improve blood circulation.
Insulin: A hormone produced by the pancreas that helps the body metabolize and use sugar, decreasing the sugar levels in the bloodstream.
Intra-aortic Balloon Pump Assist Device (IABP): A machine that can help the pumping function of the heart. It is usually inserted through an artery in the groin area and threaded backward into the descending thoracic aorta in the chest. In this location, the balloon inflates and deflates in synchrony with the heart in order to aid the blood-pumping function of the heart in people whose heart has been damaged, most often due to a heart attack.
Intracardiac Tumor: An intracardiac tumor can be any tumor of the heart, either malignant or benign. The most common tumor of the heart is a benign atrial myxoma.
Intravascular: Inside a blood vessel.
Intravascular Ultrasound (IVUS): An invasive procedure, performed along with cardiac catheterization. A miniature sound probe (transducer) on the tip of a catheter is threaded through the coronary arteries and, using high-frequency sound waves, produces detailed images of the interior walls of the arteries.
Ischemia: Condition in which there is not enough oxygen-rich blood supplied to the heart muscle to meet the heart's needs.
Lead Extraction: A lead is a special wire that delivers energy from a pacemaker or implantable cardioverter defibrillator (ICD) to the heart muscle. A lead extraction is the removal of one or more leads from inside the heart.
Leaflets: Thin pieces of tissue or flaps that make up a valve.
Left Ventricular Assist Device (LVAD): A mechanical device placed in people with end-stage heart disease whose hearts do not pump a sufficient amount of blood to keep the body healthy (heart failure). The device aids in the pumping function of the blood. Oftentimes, this is used as a step before heart transplant.
Lipid: Fat circulating in the blood.
Lipoprotein: A combination of fat and protein that transports lipids (fats) in the blood.
Loop Recorder (Event monitor): See Event monitor (above).
Low-Density Lipoprotein (LDL): A lipoprotein particle in the blood responsible for depositing cholesterol into the lining of the artery. Known as "bad" cholesterol, because high LDL is linked to coronary artery disease.
Magnetic Resonance Imaging (MRI): A test that produces high-quality still and moving pictures of the heart and large blood vessels. MRI uses large magnets and radio-frequency waves to produce pictures of the body's internal structures. No X-ray exposure is involved. MRI acquires information about the heart muscle as it is beating, creating moving images of the heart throughout its pumping cycle.
Mammary Artery (also called thoracic artery): Artery located in the chest wall and used for coronary artery bypass surgery. Most commonly kept intact at its origin, and sewn to the coronary artery beyond the site of blockage. If the surgeon removes the mammary artery from its origin to use as a bypass graft, it is then called a "free" mammary artery bypass graft.
Maze Procedure: A surgical treatment for chronic atrial fibrillation. The surgeon makes multiple incisions in the atrium to form a path or maze through which the impulse can travel to reach the atrioventricular node. After this is done, the atrium is sewn back together and a normal rhythm is more easily maintained.
Mechanical Valve: In people who require heart valve replacement surgery, it is sometimes desirable to implant a mechanical valve. A mechanical valve is made of artificial parts and functions similarly to a normal heart valve. People who have a mechanical valve implanted must take blood thinners lifelong to prevent blood clots from forming on the mechanical valve.
Metabolic Exercise Stress Test (also called metabolic stress test): A test used to measure the performance of the heart and lungs while they are under physical stress. The test involves walking on a treadmill or pedaling a stationary bike at increasing levels of difficulty, while being closely monitored.
Minimally Invasive Heart Surgery: Minimally invasive heart surgery is a technique developed to reduce the trauma associated with open heart surgery. The smaller incision that is used may allow the patient to heal more rapidly. It also helps to reduce the pain and discomfort associated with heart surgery.
Mitral Insufficiency (mitral regurgitation): A condition where blood in the left ventricle leaks back through the mitral valve into the left atrium and can back up into the lungs. The mitral valve normally opens to allow blood to flow into the left ventricle and then closes, preventing blood from backing up into the atrium during the ventricle's contraction. This may be associated with mitral valve prolapse or can develop due to other forms of heart disease.
Mitral Stenosis: A condition where the mitral valve becomes narrowed (stenotic), preventing the easy flow of blood from the left atrium into the left ventricle.
Mitral Valve: The valve that lies between the left atrium and left ventricle (main pumping chamber of the heart). This valve allows blood to flow from the left atrium into the left ventricle and then prevents the backflow of blood into the left atrium during ventricular contraction.
Morbidity Rate: The percentage of people who have complications from a medical condition or after a procedure or treatment.
Mortality Rate: The percentage of deaths associated with a disease or medical treatment.
Multigated Acquisition Scan (MUGA scan): A nuclear scan that evaluates the pumping function of the ventricles by determining the heart's ejection fraction.
Murmur: Turbulent blood flow across a heart valve that creates a "swishing" sound heard by a stethoscope. This sound can be due to a valve being too tight, leaky or occur from a congenital abnormality to the heart, such as a hole or stricture.
Myocardial Biopsy (Cardiac biopsy): An invasive procedure to obtain a small piece of heart muscle tissue that is sent to a laboratory for analysis.
Myocardial Infarction (Heart attack): See heart attack (above).
Myocarditis: Inflammation of the myocardium (heart muscle). May feel like a heart attack and appear to be one, until further testing is done.
Myocardium: Heart muscle.
Myomectomy: A surgical procedure to remove abnormally thickened heart muscle. Myomectomy is used to treat people with idiopathic hypertrophic subaortic stenosis (IHSS) or HOCM, thereby relieving the obstruction to blood flow in the left ventricle during contraction.
Nitroglycerin: A medication used to relax and dilate the blood vessels (vasodilator), improving blood flow. Nitroglycerin works very quickly and is the most common vasodilator used to treat angina.
Non-Q-Wave MI (NSTEMI or non-ST-elevation MI): A heart attack that does not cause changes known as "Q-waves" on the electrocardiogram (ECG). However, other changes in the ECG are often seen. In addition, chemical markers in the blood indicate that damage has occurred to the heart muscle. In non-Q-wave MI, a clot may block the coronary artery for a period of time, and then break up by itself or collateral circulation may help to restore blood flow. The size of the damage is fairly small; therefore, overall function of the heart is usually maintained, unless there have been multiple events. This is the most common type of heart attack in women.
Nuclear Scan: Nuclear imaging is a method of producing images by detecting radiation from different parts of the body after the administration of a radioactive tracer material.
Obesity: Abnormal or excessive fat accumulation that presents a risk to health. It is usually defined by having a body mass index (BMI, see above) of 25 or higher.
Occlusion: Blockage.
Off Pump Heart Surgery: Heart surgery done without the use of the cardiopulmonary bypass machine.
Pacemaker: A small electronic device is implanted under the skin and sends electrical impulses to the heart muscle to maintain a suitable heart rate and to prevent slow heart rates.
Palpitation: A fluttering sensation in the chest that is often related to a missed heartbeat or rapid heartbeat.
Papillary Muscles: Small muscles that are part of the inside walls of the ventricles and attach to the chordae tendinae.
Patency Rate: The likelihood that a vessel will remain open.
Pericardiocentesis (pericardial tap): An invasive procedure that involves using a needle and catheter to remove fluid from the sac around the heart. The fluid may then be sent to a laboratory for tests to look for signs of infection, autoimmune disease, or cancer.
Pericardium: The sac that surrounds the heart.
Pericarditis: Pericarditis is an inflammation of the pericardium, the sac around the heart.
Plaque: Deposits of fats, inflammatory cells, proteins, and calcium material along the lining of arteries seen in atherosclerosis. The plaque builds up and narrows the artery.
Platelets: Components of blood that aid in clotting.
Positron Emission Tomography (PET or cardiac viability study): An imaging procedure that uses radioactive tracers to create 3-dimensional pictures of the tissues inside of the body and can monitor metabolic processes.
Premature Ventricular Contractions (PVCs): An irregular heartbeat in which the lower chambers of the heart (the ventricles) beat before they are supposed to.
Prophylaxis: The prevention of disease.
Pulmonary Edema: An abnormal swelling of tissue in the lungs due to fluid build-up.
Pulmonary Hypertension: Pulmonary hypertension is high blood pressure of the pulmonary arteries.
Pulmonic Valve: The last valve through which the blood passes before it enters the pulmonary artery that lies between the right atrium and goes from the right ventricle to the lungs.
Pulse Rate: The number of heartbeats per minute. The resting pulse rate for an average adult is between 50 and 90 beats per minute.
Q-wave MI (STEMI or ST-elevation MI): A heart attack that is caused by a prolonged period of blocked blood supply. An area of the heart muscle is affected, causing changes known as "Q-waves" on the ECG and chemical markers in the blood, usually implying that the full thickness of the heart muscle was affected in the heart attack, causing that part of the muscle to die.
Radial Artery: The radial artery is a blood vessel that carries oxygen-rich blood in the forearm. You can feel the pulse of the radial artery by feeling the inside of the wrist underneath the base of the thumb.
Radionuclide Study (MUGA): See MUGA above.
Regurgitation: Leaking or backward flow.
Restenosis: The closing or narrowing of an artery that was previously opened by a procedure such as angioplasty or a stent.
Rheumatic Fever:Rheumatic fever is an inflammatory reaction (usually in response to a strep infection) that can involve the heart and heart valves.
Rheumatic Heart Disease: Rheumatic fever can lead to a condition known as rheumatic heart disease. This is usually a thickening and stenosis of one or more of the heart valves and often requires surgery to repair or replace the involved valve(s).
Rheumatic Valve Disease: Rheumatic valve disease is a consequence of rheumatic fever. It is a thickening and stenosis of one or more of the heart valves and often requires surgery to repair or replace the affected valve(s).
Right Ventricular Biopsy: The removal of a small piece of heart tissue from your right ventricle. This tissue sample is studied under a microscope to help your doctor assess your heart muscle.
Risk Factor (for heart disease): Traits people have that are linked to the development and progression of coronary artery disease. There are modifiable risk factors -- related to lifestyle and may be changed or controlled -- and non-modifiable risk factors -- related to aging and genetics and cannot be changed.
Rotablation (Percutaneous Transluminal Rotational Atherectomy or PCRA): A special catheter, with an acorn-shaped diamond-coated tip, is guided to the point of narrowing in the coronary artery. The tip spins around at a high speed and grinds away the plaque on the artery walls. The microscopic particles are washed safely away in your bloodstream and filtered out by the liver and spleen. This process is repeated as needed to allow better blood flow.
Saphenous Vein: Vein located in the leg(s) and used for coronary artery bypass surgery. It is surgically removed from the leg and sewn from the aorta to the coronary artery beyond the site of the blockage.
Septum: The muscular wall separating the right and left sides of the heart.
Sestamibi Exercise Stress Test (Sestamibi stress test, stress perfusion scan, stress Sestamibi): A diagnostic study, that uses a small amount of radioactive tracer, injected into the body, and a special camera, that detects the radiation, to produce a computer image of the heart. Combined with exercise, the study can help determine if there is adequate blood flow to the heart at rest, as compared with activity.
Silent Ischemia: Inadequate supply of oxygen-rich blood to the heart that does not cause symptoms such as chest pain, or is ignored or dismissed without being diagnosed as atherosclerosis or a decrease in oxygen delivery to the heart muscle.
Sinoatrial Node (SA or sinus node): A specialized cluster of cells in the heart that initiates the heartbeat. Known as the heart's natural pacemaker.
Sodium: A mineral found in most of the foods we eat. The largest source of dietary sodium comes from sodium chloride or table salt. Intake of sodium tends to increase the retention of water and blood pressure.
Sphygmomanometer: A device for measuring blood pressure.
Stenosis: Narrowing or restriction of a blood vessel or valve that reduces blood flow.
Stent: A small tube, inserted after angioplasty, that acts as a scaffold to provide support inside the coronary artery. The goal is to keep the artery open.
Sternum (breastbone): Bone in chest separated during open heart surgery.
Stress Test: See Exercise Stress Test.
Stroke: A sudden loss of brain function due to decreased blood flow to an area of the brain.
Stunned Myocardium: If blood flow is returned to an area of the heart muscle after a period of ischemia (lack of blood supply), the heart muscle may not pump normally for a period of days following the event. This is called "stunned" heart muscle or myocardium.
Subvalvular Aortic Stenosis: A narrowing of the flow of blood below the aortic valve in the left ventricle. It is usually caused by a membrane or thickening in the muscle in this area.
Syncope: Fainting.
Systole: The portion of the cardiac cycle in which the heart muscle contracts, forcing the blood into the main blood vessels.
Systolic Pressure: The pressure of the blood in the arteries when the heart pumps. It is the higher of two blood pressure measurements (for example, 120/80, where 120 is the systolic pressure).
Tachycardia: Rapid heartbeat. A heart rate above 90 beats per minute.
Thallium Exercise Stress Test (Stress thallium test, Perfusion scan): A type of nuclear scanning technique that uses the radioactive substance thallium. A thallium stress test combines nuclear scanning with exercise on a treadmill or stationary bicycle to assess heart function and determine if there is adequate blood flow to the myocardium.
Thrombolytic Medication (clot-buster drug): Medication used to dissolve any clots that may be blocking blood flow in arteries and veins.
Thrombus: A blood clot.
Total Cholesterol: The total amount of cholesterol in the blood.
Transesophageal Echocardiogram (TEE): An invasive imaging procedure that creates a picture of the heart's movement, valves, and chambers using high-frequency sound waves that come from a small transducer passed down your throat. TEE provides clear images of the heart's movement because the transducer is close to the heart and limits interference from air in the lungs. Echo is often combined with Doppler ultrasound and color Doppler to evaluate blood flow across the heart's valves.
Transient Ischemic Attack (TIA): A stroke-like event lasting minutes, or hours, that occurs when the brain is deprived of oxygen-rich blood, but in which the effects wear off completely after resumption of blood flow.
Trans-Myocardial Revascularization (TMR): A procedure used in people with severe heart disease who are not candidates for bypass surgery. In this procedure, an incision is made in the chest. The heart is exposed and small holes are drilled through the wall of the heart with a laser. The benefits of TMR have not been proven.
Transtelephonic Monitor: A small monitor is attached to electrode leads (usually on your finger or wrist). Your heart's rhythm is transmitted over the phone line with the aid of this device to your doctor's office.
Tricuspid Valve: The tricuspid valve is the valve that separates the right atrium from the right ventricle and prevents blood from flowing back into the right atrium during contraction of the ventricle.
Triglyceride: A fat found in the blood. Most fat found in the diet and body is in the form of triglycerides. It is often associated with a high-carbohydrate diet and if elevated, is a risk factor for heart disease. Many times people with diabetes have elevated triglycerides.
Unstable Angina: This type of chest pain is considered an acute coronary syndrome. It may be a new symptom or a change from stable angina. It may come more often, occur at rest, or feel more severe. Although this angina can be relieved with oral medications, it is unstable and may progress to a heart attack. Usually, medical treatment or a procedure is required to prevent a heart attack from developing.
Valve: Structures that maintain the proper direction of blood flow in the heart. There are four valves in the heart: the tricuspid and the mitral valve, which lie between the atria and ventricles, and the pulmonic and aortic valves, which lie between the ventricles and the blood vessels leaving the heart.
Valvuloplasty: A procedure to improve valve function. Balloon valvuloplasty is when a balloon is used at the time of cardiac catheterization to increase the area of a narrowed valve.
Variant Angina: A type of angina (chest pain) that occurs at rest; most often due to coronary spasm.
Vasodilator: A type of medication that relaxes and dilates the blood vessels, allowing increased blood flow.
Veins: Blood vessels that carry blood toward the heart. This blood is usually deoxygenated and goes back to the heart first before getting oxygen from the lungs.
Ventricles: The lower, pumping chambers of the heart. The heart has two ventricles - the right and left ventricle.
Ventricular Fibrillation: An erratic, disorganized firing of impulses from the ventricles. The ventricles quiver and are unable to contract or pump blood to the body. This is a medical emergency that must be treated with cardiopulmonary resuscitation (CPR) and defibrillation as soon as possible.
Ventricular Rupture: In people who suffer a significant heart attack, it is sometimes the case that the area of the muscle wall of the heart that is affected can become so weakened that it ruptures and leaks blood from the inner chamber of the heart.
Ventricular Septal Defect: The right and left ventricles lie next to each other in the heart. The septum is the membranous wall that separates them. A ventricular septal defect is a hole in the septum.
Ventricular Tachycardia: A rapid life-threatening rhythm originating from the lower chambers of the heart. The rapid rate prevents the heart from filling adequately with blood, and less blood is able to pump through the body.
Wolff Parkinson White Syndrome (WPW): WPW is a form of supraventricular tachycardia (fast heart rate originating above the ventricles). People with WPW have more than one electrical conduction pathway in their hearts (accessory pathways.) These electrical impulses set up a short circuit, causing the heart to beat rapidly and conduct impulses in both directions. The impulses travel through the extra pathway (shortcut) as well as the normal AV-His-Purkinje system. The impulses can travel around the heart very quickly, in a circular pattern, causing the heart to beat unusually fast. This type of arrhythmia is called re-entry tachycardia.
