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Please find below the glossary of terms used throughout the ‘Heart’ (or ‘Adult Cardiac’) section of the website.

Acquired aortic valve disease
Acquired aortic valve disease refers to abnormalities of the aortic valve that develop with age.
Allograft valves
Replacement valves recovered from the hearts of humans who have died (cadavers).
Angina pectoris
The discomfort experienced by individuals when their heart muscle does not receive sufficient blood supply. Every patient's angina is somewhat different. In some cases it causes heaviness in the chest, in others a burning sensation or discomfort in the left arm, and in some cases a pain in the left jaw.
An investigation to investigate blood vessels. A coronary angiogram usually involves a catheter being placed directly into the vessels supplying the heart with blood where dye will show the anatomy and any narrowings within the coronary arteries. A CT angiogram involves at CT scan with dye injected into the veins. This will show anatomy of the arteries around the heart as well as larger vessels in the chest.
A procedure on an artery within the body. A coronary angioplasty is usually performed by a Cardiologist where a narrowing within a coronary artery is widened with either a balloon angioplasty or with the placement of a stent within the artery. Your Heart Team consists of a cardiologist and a cardiac surgeon that will determine whether angioplasty or coronary artery bypass surgery is better suited to treat your coronary artery disease based on your your physical condition and the complexity of the disease in the coronary arteries.
Any of a variety of techniques may be used to support or repair a valve after repair. The annulus is the outer border or limit of the valve structure. An annuloplasty supports that outer ring after repair.
Antibiotic prophylaxis
Antibiotics taken before a surgical or dental procedure to prevent infection of an abnormal or artificial heart valve called prophylactic antibiotics. Specific recommendations for antibiotic prophylaxis are available from the American Heart Association.
Medications that interfere with, or inhibit, blood from clotting are sometimes recommended for patients with atrial fibrillation or an artificial valve. An example of a weak or mild anticoagulant is aspirin. An example of a more powerful anticoagulant is warfarin or coumadin. Newer types of anticoagulants are also used called NOACs (New Oral AntiCoagulants) such as Apixaban or Rivaroxaban.
The aorta is the body's largest artery (the blood vessels that carry oxygen-rich blood). Roughly the diameter of a garden hose, this artery extends from the aortic valve in the heart down through the chest and abdominal region, where it divides into a blood vessel that supplies each leg.
Aortic dissection
The aorta, the main blood vessel leading from the heart to the rest of the body, has a wall made of three layers. In rare circumstances, the layers of the aorta can separate, much as layers of plywood will separate when left in the rain. When this happens to the aorta, it is called aortic dissection. Aortic dissection is a surgical emergency. Patients who suffer from it are at significant risk of death. Several conditions like high blood pressure (hypertension) and Marfan's syndrome may lead to an aortic dissection.
Aortic valve
Four valves are in the heart with two on the left side and two on the right side. On each side there is an inflow valve to the ventricle - the main pumping chamber - and an outflow valve. The aortic valve is the outflow valve for the left ventricle, and as such opens when the ventricle squeezes blood out and then closes to keep blood from leaking back into the ventricle.
Ascending aortic aneurysms
The first portion of the aorta as it exits from the heart is the ascending aorta. Occasionally the aorta will enlarge or dilate. Such areas of dilatation are called aneurysms. When the ascending aorta dilates and becomes an ascending aortic aneurysm it may cause aortic dissection, may rupture or burst, or may case the aortic valve to leak
Atrial appendage
A portion of the left or right atrium that resembles an empty pouch. Is has little or no function but can be an area that is susceptible to blood clot formation, particularly when there is atrial fibrillation. A cardiac surgeon may propose a procedure to lower this risk of clot formation called left atrial appendage plication (oversewing) or ligation (clipping).
Atrial contraction
Atrial contraction refers to the part of the heart cycle when the atrium (or upper, low-pressure chamber) squeezes or contracts forcing blood into the ventricle (the main pumping chamber).
Atrial fibrillation
When the atrium (the upper, low pressure chamber of the heart) does not squeeze or contract at one uniform, coordinated time but instead contracts irregularly with one portion contracting well before or after another, the result is atrial fibrillation. When this happens, the atrium cannot push blood into the ventricles in the normal manner. Blood clots are also more likely to form in the atrium and anticoagulants are often prescribed.
Atrial septal defect (ASD)
Normally there is a wall or "septum" between the right and left atrium, the upper, low-pressure chambers of the heart. When there is a hole in that wall allowing blood to flow in both directions, it is called an atrial septal defect, or "ASD."
Atrioventricular Node
Although the upper chambers (the atria) and the lower chambers (the ventricles) are physically connected to one another to allow blood to flow from one to the other, from an electrical standpoint, they are normally connected to one another at only one point. This point is called the atrioventricular node. Therefore, the electrical impulse from the atrium must pass through this point to reach the ventricle. If this connection is destroyed, for example in the cardiac catheterisation lab by radiofrequency ablation ("A-V node ablation"), the electrical impulse from the atrium can no longer reach the ventricle. Regardless of what is going on in the atrium electrically- sinus rhythm, atrial flutter, or atrial fibrillation-the ventricle will beat at its own pace. In some individuals, there is an extra or "accessory" pathway from the atria to the ventricles, which results in a syndrome causing palpitations and a rapid heart rate called "Wolfe-Parkinson-White syndrome."
Atrio-ventricular valve
The valves between the atria and ventricles are called atrio-ventricular valves. The atrio-ventricular valve on the left is the mitral valve. The atrio-ventricular valve on the right is the tricuspid valve.
There are four chambers in the heart, two on the right side pumping to the lungs, and two on the left side pumping to the body. On each side there is an upper, low-pressure chamber that collects blood from the veins and delivers it to the ventricles, the main pumping chambers of the heart. These upper chambers are called the atria (plural) or atrium (singular).
Bacterial endocarditis
Occasionally a blood stream infection will settle on a heart valve and damage it. The infection is called bacterial endocarditis.
Balloon angioplasty
Balloon angioplasty is a procedure performed by cardiologists to help open narrowing of the coronary arteries. This procedure requires cardiac catheterisation and involves passing a catheter with a balloon into the artery. The balloon is then blown up in the artery to eliminate the narrow area.
Balloon valvuloplasty
Interventional cardiologists (cardiologists who concentrate their efforts on correcting conditions using catheters from inside the blood vessels) can often open up a narrow or stenotic valve by blowing up a special balloon in the valve and stretching it open.
Bicuspid aortic valve
The aortic valve normally has three leaflets or cusps. Occasionally an individual is born with a valve having only two cusps - called a bicuspid valve.
Biological valves
Artificial valves made from humans or animals, rather than from metal, are called biological valves. Examples of biological valves are porcine xenografts, human homografts or allografts, and pulmonary autografts.
Bypass Surgery
An abbreviated term for coronary artery bypass surgery
Cardiac catheterisation
Cardiac catheterisation is a procedure accomplished by passing small tubes or catheters into the heart from arteries and veins in the groin or arm. It is performed by a cardiologist with specialised training. Many conditions affecting the heart require direct measurement of pressures in the chambers or injection of dye (contrast material visible on Xray).
Cardiologists are physicians trained in Medicine who specialise in diseases of the heart.
Cardiothoracic surgeon
Cardiothoracic surgeons are surgeons who undergo specialised training in surgery of the chest and organs including the heart and lungs. In the United Kingdom surgeons generally practice either Cardiac (Heart), Thoracic (Lungs and chest wall) or Congenital (Heart and Lung disease in children). Some surgeons may practice a combination of these.
A narrow tube that can be passed inside blood vessels to the heart for diagnostic and treatment purposes.
Congenital aortic valve disease
Abnormalities present at birth are called "congenital." Congenital aortic valve disease refers to abnormalities of the aortic valve present from birth. An example would be Bicuspid aortic valve, where there are two leaflets instead of three forming the aortic valve.
Congenital mitral valve disease
Abnormalities present at birth are called "congenital." Congenital mitral valve disease refers to abnormalities of the mitral valve present from birth. An example would be a mitral valve cleft causing the valve to leak or Barlow’s type valve where there is an excess of tissue causing prolapse and leaking.
Coronary arteries
The coronary arteries are the arteries on the surface of the heart that provide blood flow to the heart muscle itself.
Coronary artery bypass grafting (CABG)
The surgical procedure to treat narrowing or "stenosis" of the coronary arteries is called coronary artery bypass, or CABG (pronounced "cabbage"). To accomplish this, cardiothoracic surgeons create bypasses around the obstructions in the coronary arteries with arteries or veins from elsewhere in the body to improve blood flow to the heart.
Coronary artery disease
Coronary artery disease is characterised by a narrowing or "stenosis" of the blood vessels to the heart resulting in inadequate blood flow to the heart muscle itself.
Diabetes mellitus
Diabetes is a common disease in which one's blood sugar is not appropriately controlled. It is a risk factor for coronary artery disease among other conditions. There are two primary types of diabetes mellitus known as type 1 and type 2 diabetes.
Diastole is the portion of the heart's pumping cycle during which the muscle relaxes to let the heart fill. The portion of the cycle when the heart empties is called systole.
Echocardiogram (Echo)
An Echo is a sound wave picture of the heart that gives information about the valves of the heart and the function of the muscular walls of the heart.
Echocardiography is the process whereby an echocardiogram is performed and interpreted.
Electrocardiogram (ECG)
The electrocardiogram is a test of the way the electrical impulses flow through the heart. Abnormalities may indicate that a heart attack has occurred in the past. If performed during symptoms suggestive of coronary artery disease angina pectoris, abnormalities may confirm the diagnosis of ischemic heart disease.
Heart attack
A heart attack occurs when the heart does not get enough blood flow leading to the death of the heart muscle. This event is also known as a myocardial infarction.
Heart failure
Heart failure is a degenerative condition that occurs when the heart muscle weakens and the ventricle no longer contracts normally. The heart can then no longer pump enough blood to the body. This may limit exercise tolerance or may cause fluid retention with swelling of the feet or shortness of breath.
Homograft valves
Homograft valves are replacement valves recovered from the hearts of humans who have died (cadavers). See also Allograft valves.
Hypertension is the medical term for high blood pressure. It has many causes and is a risk factor for a number of other medical conditions, including coronary artery disease, aortic dissection, and heart failure.
Hypotension refers to abnormally low blood pressure.
Internal mammary artery
This artery is on the inside of the chest wall and is commonly used for bypass grafting. It may also be called the internal thoracic artery. Most commonly the Left Internal Mammary artery is used to graft onto the front of the heart and is known as the LIMA graft.
This term means not having enough blood flow. When a part of the body does not receive enough blood flow, it is called ischemic.
Ischemic heart disease
When the arteries providing blood to the heart, the coronary arteries, become clogged the heart cannot get enough oxygen and nutrients. It then becomes "ischemic." This condition is called ischemic heart disease, and it is caused by coronary artery disease.
Left ventricle
The main pumping chambers of the heart are the ventricles. The heart has a right side that pumps blood to the lungs, and a left side that pumps blood to the body. The left side of the heart, therefore, must work harder than the right. Therefore the main pumping chamber of heart is the left ventricle.
Marfan's syndrome
This condition is an inherited disease affecting the bones, joints, and heart and great vessels. It can cause valves to become leaky and/or the aorta to become aneurysmal or to dissect.
Mechanical valves
Artificial valves made from metal, plastic, and/or pyrolytic carbon. They have excellent durability and most will last indefinitely.
Median sternotomy
The incision traditionally used to perform heart surgery in which the sternum or breastbone is divided down the middle from top to bottom.
Minimally invasive heart surgery
The term minimally invasive heart surgery is used to describe a variety of approaches that reduce the trauma of surgery and speed recovery. These approaches include "keyhole" surgery, and heart surgery without the use of a heart lung machine, and many other techniques.
Mitral valve
There are four valves in the heart, two on the left side and two on the right side. On each side there is an inflow valve to the ventricle - the main pumping chamber - and an outflow valve. The mitral valve is the inflow valve for the left ventricle. As such, it closes when the ventricle squeezes blood out to the body, and then opens to let more blood into the ventricle.
Myocardial infarction
When the heart does not get enough blood flow, the heart muscle dies. This is called a myocardial infarction or, in more common language, a heart attack.
Paroxysmal atrial tachycardia
The normal heart rhythm is set by the sino-atrial node, an area of specialised tissue in the atrium. Occasionally a very fast rhythm or "tachycardia" will originate in the atrium. This is "atrial tachycardia." When it occurs suddenly and intermittently, it is called "paroxysmal."
The thin but very strong layer of fibrous tissue that encases the heart. It is normally made up of layers that slide easily over one another. Diseases can cause thickening of the tissue or fluid to build up between the layers which can adversely affect the heart function. Procedures to remove the pericardium and called pericardiectomy. Procedures to make a hole within the pericardium to allow fluid to drain is called pericardial window.

Some xenograft heart valve are made with pericardial tissue from healthy animals. These are called pericardial tissue valves.
Premature atrial contractions
The normal heart rhythm is set by the sinoatrial node, an area of specialised tissue in the atrium. Occasionally an early or "premature" beat or contraction originates from the atrium.
An artificial replacement part, such as an artificial valve, is called prosthesis.
Pulmonary autograft valves
A new approach for replacement of a diseased aortic valve involves moving the patient’s own pulmonary valve (the valve on the right side of the heart that leads to the pulmonary artery and the lungs just as the aortic valve leads to the aorta and the body) into the aortic position to replace a stenotic or regurgitant aortic valve.
Pulmonary vein isolation
A procedure to create scar tissue around the junction of the pulmonary veins and the left atrium to inhibit abnormal electrical activity causing atrial fibrillation. It is part of the procedure used in atrial fibrillation surgery.
Radial artery
An artery in the forearm of the body that supplies blood to the hand. It may be used as a graft for coronary artery bypass surgery as usually the hand is supplied by two arteries, the radial artery and the ulnar artery. The radial artery is often used for catheterisation of the heart for angiograms.
When a valve leaks it is said to be "regurgitant," or to exhibit regurgitation.
When the breastbone is divided to expose the heart, it is called a sternotomy. A resternotomy is the subsequent opening of the chest by dividing the breastbone again. If it is done soon after an operation, for example bleeding, it can be easy to perform. If it is performed months after the initial operation, it can be more complex to perform.
Rheumatic fever
Streptococcal infection occasionally causes a more generalised disease or inflammation in the joints and heart valves. In the heart valves this may progress with time to ultimately damage the valves sufficiently enough that they must be replaced. This is called rheumatic heart disease.
Saphenous vein
This vein on the inside of the leg running from the ankle to the groin can be used to make bypasses from the aorta to the coronary arteries. There is a deep venous system that normally does most of the work draining blood from the legs back to the heart. The saphenous vein is part of the superficial system that normally does only about 10% of the work. The saphenous vein can, therefore, be taken out without harming the patient or adversely affecting the leg. It is common for the leg from which the vein is harvested to swell slightly.
Senile aortic calcification
As some individuals get older, calcium may accumulate on the leaflets of the aortic valve. The normal functioning of the valve requires that the leaflets open and close completely. When this calcium accumulates, the leaflets can no longer function normally. This condition is called senile (referring to older age) calcification.
Sinoatrial node
The normal "pacemaker" for the heart is an area of specialised cells in the atrium called the sinoatrial or "SA" node. These cells automatically send out an electrical impulse to the rest of the heart telling it to contract.
Sinus rhythm
The normal rhythm of the heart originates in the sinoatrial node. It is called sinus rhythm.
Narrowing of a valve or an artery is called stenosis. A stenotic valve does not open completely and therefore it obstructs or blocks blood from moving through it normally. An artery can become stenotic as well, such that there is obstruction of blood flow through it to the organs of the body.
Stress test
A variety of tests usually fall under the general term of stress test. These include stress, dobutamine or stress echocardiography, and traditional electrocardiographic stress tests. Any of these may reveal inadequate blood flow to the heart or ischemia. During a stress test, the heart is monitored by any one of these means both at rest and with exercise or stress to see if there is a difference in blood flow.
A fainting spell or loss of consciousness is called syncope.
The part of the cycle during which the muscle contracts to empty the heart is called systole. The filling portion is diastole.
The word thoracic is the adjective form of the noun "thorax." The word thorac derives from the Greek and Latin words for breastplate or chest. The term thorax refers to the area of the human body that is located between the neck and the abdomen. The thorax contains the heart, lungs, oesophagus, and great vessels surrounded by the breastbone or sternum in front, the ribs on each side, and the vertebral column in the back.
Tricuspid aortic valve
The normal aortic valve normally has three cusps or leaflets and is therefore called tricuspid (as opposed to a bicuspid aortic valve).
Tricuspid valve
There are four valves in the heart, two on the left side and two on the right side. On each side there is an inflow valve to the ventricle - the main pumping chamber - and an outflow valve. The tricuspid valve is the inflow valve for the right ventricle, and as such closes when the ventricle squeezes blood out to the lungs and then opens to let more blood in to the ventricle.
Varicose veins
The veins in the leg may become weakened and enlarged, particularly after blood clots have formed in them. Such thin-walled, enlarged veins are called "varicose" and cannot be used for coronary bypass grafts.
Vena Cava
The vena cavae (plural of vena cava) are two large veins that return oxygen-poor blood into the right atrium of the heart. The superior vena cava delivers oxygen-poor blood to the atrium from the upper half of the body (arms and head), and the inferior vena cava delivers oxygen-poor blood into the atrium from the lower half of the body (abdomen and legs).
The main pumping chamber of the heart is the ventricle. The right side pumps deoxygenated blood to the lungs and the left side pumps blood around the body.
Ventricular function
The performance or strength of the main pumping chamber of the heart is called "ventricular function." Good left ventricular function is considered when more than 50% of the blood is ejected from the ventricle during each contraction.
Xenograft valves
Artificial valves made from animal tissue are called xenografts. Most often the valves are made from pig aortic valves. More recently, some valves have been made from cow tissues.