A Glossary of Heart Disease Terms
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 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: 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.
Heart Failure (congestive heart failure, CHF): A progressive condition where the heart muscle weakens and cannot pump blood efficiently. Fluid accumulates in the lungs, hands, ankles, or other parts of the body.
Heart Lung 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 heart muscle that is "resting" 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. 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.