Heart Disease Glossary of Terms
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 heart 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, usually until the patient has a 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 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, it is 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 to help block abnormal impulses from reaching 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.