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Terminology in Valvular Heart Disease
- Allograft
- Human tissue ...usally cadaver tissue procured shortly after death and preserved with one of several freezing techniques. Since the donor is a different individual than the recipient, rejection can occur. Same meaning as the term "Homograft"
- Angina
- Characteristic pain (in the thorax, arm, jaw, or back) which occurs during exertion in patients with certain kinds of heart disease. Anginal pain is usually prompted by stress (either physical or emotional) and relieved by rest, or specific medications which improve the delivery of blood to the heart.
- Anticoagulation
- Treatment of clotting disorders with medications that impair the ability of the blood to form clots. The most commonly used blood thinner is warfarin (also known as Coumadin®)
- Anticoagulants
- Blood Thinners...medications which reduce or impair the ability of the blood to form clots. These medications are used to retard clot formation on artificial devices or in certain. The most common medications are oral warfarin (or Coumadin®) and intravenous heparin
- Annulus
- A ring of tough fibrous tissue at the base of the heart. This ring supports and anchors the heart valve(s) into the heart itself. There are 4 valve annuli...one each for the tricuspid, mitral, aortic, and pulmonary valves. These rings of fibrous tissue all converge together in the middle of the heart, and area known as the fibrous skeleton of the heart.
- Aorta
- The main blood vessel carrying all of the fresh blood out of the heart to the body. The aorta comes directly out of the heart and then courses through the body providing branches which deliver nourishing blood supply to every organ and tissue
- Aortic Root
- The opening at the junction between the heart chamber and the aorta itself. The root is characterized by an encircling band of firm fibrous tissue (the annulus) and the leaflets of the aortic valve.
- Aortic Valve
- A three leaflet valve which naturally occurs at the junction between the left ventricle and the aorta. The aortic valve protects the left ventricle from being swamped with blood coming backwards after ejection from the heart.
- Aortic Stenosis
- A narrowed aortic valve. The narrowing can be caused by leaflet fusin, thickening, calcification, infection, or from a congenital malformation of the valve. Regarless, once the opening mechanism of the valve is restricted,
- Atrial appendage
- Small outpouching of the atrial chamber, usually a remnant of the developmental process..
- Atrial Fibrillation
- A chaotic rhythm of the heart.... where the upper chamber of the heart quivers at rate of 600 times per minute or more. Only part of the contraction signals reach the lower chamber. Thus the actual rte of contraction in the lower pumping chambers is around 80 to 120/min. In AF, the patient feels an irregular heart beat (palpitations). If the rate goes too fast, medication need to be administered to slow the heart rate. Chronic AF can be associated with an increased risk of stroke so anticoagulation with Coumadin is recommnded.
- Bicuspid
- Two leaflets instead of three...a semilunar valve that was formed with only 2 leaflets (and thus only 2 commissures). These valves have abnormal flow patterns, are usually obstructive, gradually wear out and calcify, and are detected by a significant murmer.
- Bioprosthesis
- Tissue valve...another way of specifying a valve made from animal (or human) preserved tissue.
- Bovine
- Another name for tissue from a cow (animal tissue)
- Calcification
- Deposition of lumps or granules of calcium within the matrix of the tissues. A sign of chronic low-grade inflammation and/or other forms of local cell damage (such as rejection)
- Cardiopulmonary Bypass (CPB)
- Another name for extracorporeal circulation (ECC). For a brief tour of ECC, click here.
- Chordae tendinae
- Fine fibrous chords (or tendons) that suspend the native mitral (and tricuspid) valve tissue to the heart chamber below. The chordae tendinae keep the valve tissue from flailing backwards cause leakage of the valve.
- Commissure
- The fusion point where two valve leaflets meet and anchor to the supporting structures of the heart.
- Congenital/Congenital Heart Disease
- Alternations in the normal heart anatomy present in the newborn child. Not all of these are detected at birth. Some are first manifest or detected in adulthood, but still are a consequence of a malformation in the developing fetus leading to a structural abnormality of the heart at the time of birth and beyond
- Congestive Heart Failure
- Build up of fluid in the body...a condition of generalized fluid retension causing swelling and shortness of breath. When the heart cannot deliver enough blood to the body, then fluid is retained in the lungs or other tissues. Patients with severe heart failure are incapacitated by symptoms of shortness of breath, air hunger when laying flat, fatigue, swelling in the feet, and other problems. Reduced life expectancy is common. There are many causes, including valve or coronary disease.
- Device Failure
- Mechanical breakage or malfunction (of any kind) in a medical device
- Embolism
- The name of an event where clots detach from their source and migrate through the circulation to another blood vessel or body organ.
- Endocarditis or SBE
- Valve Infection...Subacute Bacterial Endocarditis (SBE) refers to a progressing infection of the heart valve, leading to destruction of the valve leaflets, fibrous support structures, and other consequences.
- Extracorporeal Circulation (ECC)
- The technique of mechanically circulating the blood so the heart doesn't have to. The device used for ECC is called the heart-lung machine or the cardiopulmonary bypass circuit. This device drains the blue blood from the patient, places oxygen in the blood, and returns (or pumps) the red blood back into the aorta for distribution to the whole body. To prevent clotting in the heart-lung circuit, strong anticoagulation with heparin is needed.
- Gradient
- Pressure difference...the term "gradient" is used to specify the difference in blood pressure before and after a blockage or stenosis. The gradient is a pressure difference (calculated by subtracting the higher pressure before a blockage from the lower pressure beyound the blockage). The severity of a blockage and the impact on circulation hemodynamics can be estimated by the magnitude of the gradient. This is particularly useful in estimating the severity of obstructive heart valve conditions.
- Heart-Lung Machine
- Another term for machine which provides extracorporeal circulation (ECC)
- Hemodynamics
- Hydrolic performance...a term loosely used to describe the throughput of blood when referring to the performance of a heart, circulation, or a device in the circulatory system. There are several key measurements which compose the assessment of hemodynamic performance, such as the flow (i.e. volume of blood per minute), the flow velocity, and/or the pressure gradient needed to achieve the measured flow.
- Hemorrhage
- Bleeding
- Homograft
- Human tissue ...usally cadaver tissue procured shortly after death and preserved with one of several freezing techniques. Since the donor is a different individual than the recipient, rejection can occur. Same meaning as the word "Allograft".
- Insufficiency
- Leakage...Regurgitation...a valve condition where the valve does not seal completely, and blood leaks backward
- Left Atrium
- The upper (or "priming") pumping chamber on the left side of the heart. The left atrium sits above the mitral valve and gently forces blood across the mitral valve into the left ventricle. This actions "primes" the lower pumping chamber to improve efficiency. At the same time, the left atrium provides a temporary storage site for blood returning from the lungs during the time that the left ventricle is actually squeezing.
- Left Ventricle
- The main pumping chamber of the heart. Oxygen-rich blood is pumped out of the left ventricle during a heart contraction and ejected into the aorta for distribution throughout the body.
- Mechanical (Valve)
- Man-made or artificial...a term which defines a replacement valve made solely (or mostly) from man-made materials. An older term (which is now colloquial) is "metal" valve. However, the current mechanical heart valves on the market are not made from metal. Instead they are made from a compressed carbon material which is hard enough and yet free of significant friction to provide long term durability at the same time providing relative freedom from wear, breakage or excessive clotting. Mechanical valves are fabricated while the tissue valves are procurred (from animal sources).
- Mitral Valve
- The left ventricle pumps blood forward into the body. The mitral valve prevents blood from regurgitating backwards into the upper heart chambers during cardiac contractions.
- Orthotopic
- In the natural anatomic position (right where nature intended it to be).
- Pannus
- Fibrotic tissue which grows around a newly implanted prosthetic heart valve. Vigorous growth of this healing tissue can freeze or obstruct a replacement valve. Pannus formation may be related, in part, to the design or materials of the prosthesis, or to the degree of anticaoglation.
- Papillary Muscles
- Muscular extensions of the heart chamber which provide support and anchors for the chordae tendinae.
- Patient-Size mismatch
- When the new replacement valve is not large enough for the patients needs. Usually this occurs when the valve annulus is abnormally small or the surgeon cannot (or does not) enlarge the annulus to the patients needs.
- Porcine
- Another name for tissue from a pig (animal tissue)
- Primary Tissue Failure
- Term used to describe the gradual disruption of the leaflets of an implanted tissue valve prosthesis. Most commonly used to describe the type of degeneration seen from non-infectious breakdown of the leaflets.
- Pulmonary Artery
- The major blood vessel that delivers blue, or oxygen-poor, blood from the right ventricle to the lungs where oxygen is acquired. The blood pressure in the pulmonary artery is about one-quarter of that measured in the aorta.
- Pulmonary Veins
- The large veins leading red blood into the left heart from the lungs after oxygen has been absorbed.
- Regurgitation
- Leakage...Insufficiency...a valve condition where the valve does not seal completely, and blood leaks backward
- Rheumatic
- A term used to classify heart problems that are specifically caused by the sequelae of acute rheumatic fever. This childhood illness is caused by the bodies immune response to the Streptococcus organism, a common pathogen in sore throats. Rheumatic involvement of the heart valves causes fibrosis, scarring, and calcification of the valve tissues later in life.
- Rheumatic Fever
- A serious inflammatory condition which follows Streptococcal pharyngitis (i.e. "Strep throat"). Acute rheumatic fever can destroy the heart valves., or leave them vulnerable to scarring, thickening, calcification, and fusion of the leaflets later in life.
- Right atrium
- The upper (or "priming") pumping chamber on the right side of the heart. The right atrium sits above the tricuspid valve and gently forces blood across the tricuspid valve into the right ventricle. This actions "primes" the lower pumping chamber to improve efficiency. At the same time, the right atrium provides a temporary storage site for blood returning from the lungs during the time that the right ventricle is actually squeezing.
- Right Ventricle
- The pumping chamber on the right side of the heart which pumps oxygen-poor blood into the pulmonary artery on its way towards the lungs.
- Semilunar
- A term used to indicate the "half-moon" shape of a single valve leaflet. The aortic valve is the classic semilunar valve, with 3 separate "half-moon"shaped leaflets attached to the fibrous annulus. The pulmonary valve is of the same configuration.
- Stenosis
- Obstruction...a narrowing of the flow channel or orifice such that obstruction to blood flow occurs
- Subcoronary
- Literally "underneath the coronary arteries". In valve surgery, this term is used to describe a new valve which is implanted below the coronary arteries and above the muscular outflow tract of the ventricle.
- Thromboembolism
- Both clotting and embolic migration...in the same patient
- Thrombosis
- Clotting...The formation of blood clots on, or inside, of a blood vessel, heart chamber, or medical device
- Tissue (Valves)
- Animal valves...This type of replacement heart valve is procurred from animals, usually at the time of commercial meat processing. The heart tissues are recovered and processed. Leaflet and valve tissues are inspected and the poor quality specimens are rejected. The highest quality leaflet tissues are preserved and stiffened with a tanning solution (usually glutaraldehyde). Finally, the leaflets are mounted on a frame which facilitates suturing of the valve into the patients heart. Human homograft valves are also tissue valves, but are less commonly referred to by this name.
- Trileaflet
- A valve with 3 separate leaflets. In the human, these include the aortic and pulmonayr valves. Technically, the Tricuspid valve is also a 3 leaflet valve, although this term is rarely used for the tricuspid valve.
- Tricuspid
- The valve which sits between the upper and lower chambers on the right side of the heart. The tricuspid valve typically has 3 leaflets. A competant tricuspid valve prevents blood from backing up into the veins during contraction of the right heart.
- Vena Cava
- The large veins leading blue or unoxygenated blood into the right heart from the body.
- Ventricle
- A name used for the muscular pumping chamber. In the human, there are two venticles, the right and the left. The left ventricle pumps under much higher pressure and delivers the red or oxygen-containing blood to the aorta for distribution to the whole body.
- Xenograft
- Animal tissue...a section of tissue removed from an animal, processed (in a variety of ways) and then transplanted into a human host. Since the animal tissue is foreign to the human, rejection is likely. Processing methods to reduce the potential for rejection are utilized.
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