tachycardia Rapid heartbeat (more than 100 beats per minute in an adult).
temporal lobes The lower side of each half of the main part of the brain (the cerebrum).
tetralogy of Fallot A four-part congenital heart defect including a displaced aorta, a narrowed pulmonary valve, a hole in the ventricular septum, and a thickened wall in the right ventricle.
thallium stress test A radioisotope diagnostic stress test for defining areas of the heart with decreased blood flow. It can be done either with exercise or with a drug, dipyridamole (Persantine), that causes the heart blood flow to increase as it would during exercise. The electrocardiogram (ECG) is taken with the nuclear scans.
thrombus A blood clot inside a blood vessel.
tissue plasminogen activator (TPA) Clot-dissolving substance that can be produced in the body or through genetic engineering techniques. Such substances have become important in the treatment of heart attack victims. (Other commonly used clot-dissolving substances include streptokinase and APSAC.)
transdermal Delivered through the skin.
transient ischemic attack (TIA) Also called ministroke temporary symptoms resembling those of a stroke (transient paralysis, speech problems, blindness in one eye, etc.), which result from a disruption in blood flow to the brain. TIAs are usually of short duration (a few minutes), but maybe warning signs of an impending permanent stroke.
tricuspid regurgitation (insufficiency) The inability of the tricuspid valve to close properly, thereby allowing blood to leak back into the right atrium.
tricuspid stenosis Narrowing ‘or stiffness of the valve between the right atrium and the right ventricle. A rare disorder that usually affects people who have had rheumatic fever.
tricuspid valve A valve consisting of three cusps located between the upper and lower chambers (atrium and ventricle) of the right side of the heart.
triglyceride A fatty substance (lipid) found in the body’s fatty (adipose) tissues. High levels are found in diabetics and may play a role in atherosclerosis.
Type A behavior pattern Characterized by a deeply ingrained struggle to overcome real and imagined obstacles imposed by events, by other people, and especially by time. Resulting traits maybe impatience, competitiveness, irritability, anger, suspicion, and hostility. People who display this behavior may beat greater risk for heart disease.
Type B behavior pattern Denoted by the lack of Type A traits. Type B people are less driven, less competitive, and more easygoing than Type A people.