Glossary 

Below is a glossary of terms related to stem cell research and clinical trials at the Stem Cell Center. For questions about any of these terms, please call the center at 832-355-9405.

Acute myocardial infarction (AMI)—The medical term for a "heart attack." Acute myocardial infarction results from a blockage in one or more of the blood vessels leading to the heart. Damage to the heart muscle results, due to the lack of blood flow.

Adult stem cell—An undifferentiated cell found among differentiated cells in a tissue or organ. The stem cell can renew itself and change to yield all the specialized cell types of the tissue or organ.

Akinesia—A lack of myocardial wall motion.

Allogeneic—A graft or tissue from someone other than the patient such as a donor or other third-party source.

Angina or angina pectoris—Chest pain that occurs when diseased blood vessels restrict blood flow to the heart.

Angiogenesis—A new blood vessel growth.

Angiography—An x-ray technique in which dye is injected into the chambers of your heart or the arteries that lead to your heart (the coronary arteries). The test lets doctors measure the blood flow and blood pressure in the heart chambers and see if the coronary arteries are blocked.

Angioplasty—A nonsurgical technique for treating diseased arteries by temporarily inflating a tiny balloon inside an artery.

Autologous—Relating to self. Autologous stem cells are those taken from the patient's own body.

Balloon catheter—A long tube-like device with a small balloon on the end that can be threaded through an artery. Used in angioplasty or valvuloplasty.

Bone marrow—The soft spongy material in the center of bones that produces all of the body's blood cells.

Bone marrow aspiration and biopsy—The removal of a small portion of bone marrow using a small needle followed by microscopic evaluation of the cells present.

Bone marrow stem cell—Multipotent stem cells from bone marrow; types include hematopoietic stem cells and mesenchymal stem cells.

Coronary artery bypass graft surgery (CABG)—An operation in which a section of vein or artery is used to bypass a blockage in a coronary artery allowing enough blood to flow to deliver oxygen and nutrients to the heart muscles. CABG is performed to prevent heart attacks and to relieve chest pain.

Cardiac catheterization—A procedure that involves inserting a fine, hollow tube (catheter) into an artery, usually in the groin area, and passing the tube into the heart. Often used along with angiography and other procedures, cardiac catheterization has become a primary tool for visualizing the heart and blood vessels and diagnosing and treating heart disease.

Cardiomyocytes—Cardiac muscle cells.

Cardiomyopathy—A disease of the heart muscle that leads to generalized deterioration of the muscle and its pumping ability.

Collateral circulation—Blood flow through small, nearby vessels in response to the blockage of a main blood vessel.

Congestive heart failure (CHF)—A condition in which the heart cannot pump all the blood returning to it, leading to a backup of blood in the vessels and an accumulation of fluid in the body's tissues, including the lungs.

Coronary arteries—Two arteries arising from the aorta that arch down over the top of the heart and divide into branches. They provide blood to the heart muscle.

Coronary occlusion—An obstruction of one of the coronary arteries that hinders blood flow to the heart muscle.

Coronary thrombosis—Formation of a clot in one of the arteries carrying blood to the heart muscle. Also called coronary occlusion.

Cytokines—Hormone-like chemicals synthesized by lymphocytes (and other cells) which have a variety of localized effects such as stimulating cell proliferation.

Echocardiography—A method of studying the heart's structure and function by analyzing sound waves bounced off the heart and recorded by an electronic sensor placed on the chest. A computer processes the information to produce a one-, two- or three-dimensional moving picture that shows how the heart and heart valves are functioning.

Ejection fraction—A measurement (%) of blood that is pumped out of a filled ventricle (lower chamber of heart). The normal rate is 60 percent or more.

Electrocardiogram (ECG or EKG)—A test in which several electronic sensors are placed on the body to monitor electrical activity associated with the heartbeat.

Engraftment—The process in which transplanted tissue "takes" and begins to function normally. In the case of stem cell transplants, engraftment refers to the time when new blood cells are beginning to be produced.

Enlarged heart—A state in which the heart is larger than normal due to heredity, long-term heavy exercise, or diseases and disorders such as obesity, high blood pressure and coronary artery disease.

Exercise stress test—A common test for diagnosing coronary artery disease, especially in patients who have symptoms of heart disease. The test helps doctors assess blood flow through coronary arteries in response to exercise, usually walking, at varied speeds and for various lengths of time on a treadmill. A stress test may include use of electrocardiography, echocardiography and injected radioactive substances. Also called an exercise test, stress test or treadmill test.

Fibrillation—Rapid, uncoordinated contractions of individual heart muscle fibers. The heart chamber involved can't contract all at once and pumps blood ineffectively, if at all.

Heart failure—A chronic, progressive cardiac condition in which a damaged heart fails to beat efficiently and deliver enough blood to meet the body's needs

Hematopoietic stem cell—A stem cell from which all cells of the immune system and all red and white blood cells and platelets develop.

Holter monitor—A portable device for recording heartbeats over a period of 24 hours or more.

Human leukocyte antigens (HLA)—Special marker proteins found on white blood cells. HLA tissue typing is done to determine whether recipient cells and potential donor cells "match."

HLA Typing—A series of tests done before a transplant to determine how closely the tissues of a donor and recipient match.

Hypertrophic cardiomyopathy—Disease of the myocardium produced by the enlargement of the cells of the myocardium; often the result of increased oxygen demand in ischemic heart disease.

Ischemic heart disease—Also called coronary artery disease and coronary heart disease, this term is applied to heart problems caused by narrowing of the coronary arteries, thereby causing a decreased blood supply to the heart. A form of heart disease whose primary manifestations result from myocardial ischemia due to atherosclerotic CAD. This term encompasses a spectrum of patients ranging from the asymptomatic preclinical phase to acute myocardial infarction and sudden cardiac death.

Ischemic cardiomyopathy—Heart muscle disease caused by deficiency of blood flow; sometimes referred to as heart failure, in which the heart becomes weak, enlarged and does not pump blood effectively.

Magnetic resonance imaging (MRI)—A technique that produces images of the heart and other body structures by measuring the response of certain elements (such as hydrogen) in the body to a magnetic field. When stimulated by radio waves, the elements emit distinctive signals in a magnetic field. MRI can produce detailed pictures of the heart and its various structures without the need to inject a dye.

Mesenchymal stem cells—Also known as bone marrow stromal cells, mesenchymal stem cells are rare cells mainly found in the bone marrow that can give rise to a large number of tissue types such as bone, cartilage (the lining of joints), fat tissue and connective tissue (tissue that is in between organs and structures in the body).

Mesenchymal precursor cell (MPC)—Same as  mesenchymal stem cell (MSC).

Multipotent—Ability of a single stem cell to develop into more than one cell type of the body.

Myocardiocytes—Heart muscle cells (cardiac myocytes).

Myoblast—A cell that is a precursor to muscle fibers; myoblast cells have limited differentiation capability.

Myocytes—A muscle cell.

Myogenesis—The development of muscle tissue.

Neovascularization—The formation of new capillaries and blood vessels to supply ischemic tissue.

Percutaneous coronary intervention therapy (PCI)—A coronary angioplasty procedure performed by a doctor who threads a small device into a clogged artery to open it, thereby improving blood flow to the heart. A lack of blood supply to the heart muscle can cause lasting heart damage. PCI therapy is used as an alternative treatment to coronary artery bypass surgery (CABG).

Percutaneous transluminal coronary angioplasty (PTCA)—See angioplasty.

Proliferation—Expansion of a population of cells by the continuous division of single cells into two identical daughter cells.

Revascularization—A procedure to restore blood flow to the tissues. Coronary artery bypass surgery is an example of a revascularization procedure.

Self-regeneration—For cells, the ability to divide and produce more copies of itself.

Somatic stem cells—Adult stem cells. 

Stem cells—Special cells in the body that are able to transform into other cells. It is possible for stem cells to transform into heart cells, nerve cells or other cells of the body, possibly helping to improve the function of failing organs, including the heart.

Stent—A device made of expandable, metal mesh that is placed (by using a balloon catheter) at the site of a narrowing artery. The stent is then expanded and left in place to keep the artery open.

Stenosis—The narrowing or constriction of an opening, such as a blood vessel or heart valve.

Thrombolytic therapy—Intravenous or intra-arterial medicines that are used to dissolve blood clots in an artery.

TIMI flow grade—Classification used by the Thrombolysis in Myocardial Infarction trial group to indicate perfusion of an infarcted related artery (IRA) that improved from visual grade 0 to grade 2 or 3 (partial or full reperfusion).

Vein—Any one of a series of blood vessels of the vascular system that carries blood from various parts of the body back to the heart, returning oxygen-poor blood to the heart.

Ventricle (right and left)—One of the two lower chambers of the heart.

Ventricular fibrillation—A condition in which the ventricles contract in a rapid, unsynchronized fashion. When fibrillation occurs, the ventricles cannot pump blood throughout the body.

Ventricular tachycardia—An arrhythmia (abnormal heartbeat) in the ventricle characterized by a very fast heartbeat. 

Updated February 2016