anemia  A reduction in the normal amount of hemoglobin or the number of red blood cells in the circulation.  Anemia may be a symptom of iron deficiency, chronic bleeding, or some other underlying disorder.

angina  A pressure or an intense chest pain resulting from a reduced oxygen supply to the heart muscle.

angiogram An X-ray of blood vessels or other part of the cardiovascular system.

angiopraphy  A diagnostic procedure in which a contrasting dye is injected into the bloodstream to make blood vessels or heart chambers visible on an X-ray image.

angioplasty  Therapeutic procedure in which a catheter with a deflated balloon at the tip is inserted into a narrowed artery. The balloon is then inflated at the site of narrowing to widen it.

angiotensin  A blood chemical that constricts blood vessels, thereby raising blood pressure.

angiotensin-converting enzyme (ACE) inhibitors  Drugs that inhibit the action of angiotensin and that are used to treat high blood pressure for congestive heart failure.

antiarrhythmics  A group of drugs used to treat irregular heart beats (arrhythmias)

anticoagulants  Drugs that suppress the blood clotting process.

antihypertensives  Drugs to treat high blood pressure.

aorta  The largest artery in the body.  It receives blood from the left ventricle of the heart; the blood is then distributed through a branching system of arteries to all parts of the body.

aortic regurgitation (insufficiency)  Failure of the aortic valve to close properly, allowing some blood to flow back into the left ventricle with each heartbeat instead of forward into the circulation.

aortic stenosis  A narrowing or stiffness of the aortic valve causing an obstruction to blood flow; this results in an increased workload for the heart.

aortic valve  The valve that controls the flow of blood between the aorta and the left ventricle, the heart's major pumping chamber.

arrhythmia  Deviation from the normal heartbeat rhythm because of a disturbance in the electrical impulses to the heart.

atrial fibrillation  An abnormal heart rhythm in which the heart's atria contract at an excessive and irregular rate.

atrioventricular (AV) node   It is the small mass of conduction tissue, located between the upper and lower chambers of the heart, through which electrical impulses pass, controlling heart rhythm pass.

atrium  (plural: atria)  One of the two upper chambers of the heart. the left atrium receives newly oxygenated blood form the lungs, the right atrium receives deoxygenated blood form various parts of the body.

autonomic nervous system  The involuntary nervous system that controls unconscious body functions such as heart rate and blood pressure.

beta-adrenergic receptors  Nerve receptors that receive and act on nerve impulses that increase the heart rate, dilate blood vessels, and regulate certain metabolic functions.

beta blockers  A group of medications used to treat angina, hypertension, and cardiac arrhythmia by blocking nerve receptors, thereby reducing the force and rate of the heartbeat.

bradycardia  An abnormally slow heart rate, generally defined as less than 60 beats per minute in adults.

calcium channel blockers  A group of drugs used in treatment of angina, hypertension, and cardiac arrhythmias.  They work by inhibiting the effect of calcium on the muscles of arteries, thereby reducing the degree of contraction.  this results in a decrease in the workload of the heart, a decrease in blood pressure, and improved circulation of blood.

cardiac arrest  Incident during which the heart stops beating and loss of consciousness occurs because of cutoff of blood flow to the brain.  It is usually the result of ventricular fibrillation, in which the heart's ventricles twitch randomly and ineffectively rather than beating in a rhythmic fashion to pump blood form the heart. A complete cessation of all heartbeats can also cause a cardiac arrest.

cardiac catheterization  Insertion of a catheter through the blood vessels into the chambers of the heart to measure pressure or to inject a dye to visualize the coronary arteries.

cardiac cycle  The cycle of activities associated with one heartbeat.

cardiologist  A physician specializing in the diagnosis and treatment of disorders of the heart

cardiomyopathy  A term denoting any disease of the heart muscle.

cardiopulmonary  bypass machine (heart lung machine)  The machine that takes over the body's heart and lung functions during open heart surgery.

cardiovascular  Of or pertaining to the heart and blood vessels.

cardioversion  Use of an electrical shock to restore normal heart rhythm.

catheter  A flexible  tube is inserted into a blood vessel or cavity for the purpose of examination, drainage of fluid, or other procedures.

cerebrovascular accident  The sudden blockage of a blood vessel in the brain caused by an embolus, or thrombosis, and resulting in decreased blood circulation in the brain.  Also may result from a ruptured blood vessel that causes a cerebral hemorrhage.

circulatory system  The system that is made up of the heart and blood vessels and is responsible for circulating blood throughout he body, providing the tissues with oxygen and nutrients, and removing waste products.

computerized tomography (CT) scan  A diagnostic technique involving the use of computers and multiple X-ray images to produce cress-sectional images of body tissue.  this technique provides more clearly detailed images than traditional X-ray.

congenital heart defects  Abnormalities of the heart existing at birth.

congestive heart failure  Inability of the heart to pump sufficient blood, resulting in an accumulation of fluids in the lungs, abdomen, and legs. This condition usually develops over a period of years, but may also result from a heart attack.

defibrillation  An electric shock administered to the heart to stabilize an irregular heartbeat or restore a normal heartbeat after cardiac arrest.

digitalis  A drug derived from the foxglove plant and used in the treatment of heart failure and abnormal heart rhythms. Digitalis works by strengthening the pumping action of the heart, thereby improving blood circulation, or by slowing sown some of the electrical impulses from the atria to the ventricles. The most commonly used form of this drug is digoxin.

dilated cardiomyopathy  A disorder in which muscle cells in the walls of the heart do not function normally; the walls enlarge an dilate, and heart failure develops

diuretics  Medications used to treat fluid retention by increasing the kidney's output of urine and the excretion of sodium from the body.  Effective in the treatment of hypertension and heart failure.

dyspepsia  the medical term for indigestion.

dyspnea  Shortness of breath or difficulty breathing.

edema  A swelling of parts of the body because of fluid retention.

electrocardiogram (ECG OR EKG)  A visual record of the heart's electrical activity.

electrocardiography  A diagnostic procedure that records the electrical activity of the heart muscle.

embolism, embolus, emboli  A clot or other substance carried in the bloodstream form one site to another, causing the blockage of an artery.

endocarditis  Inflammation of the interior lining of the heart and heart valves; generally occurs because of bacterial infection or rheumatic fever.

endocardium  The interior ling of the heart.

exercise stress test  An electrocardiogram that is done while a person exercises, usually on a treadmill or a stationary bicycle.