(Encyclopedia) Heart, river, 180 mi (290 km) long, rising in the low prairie country near the Little Missouri River, SW N.Dak., and flowing E to the Missouri at Mandan, N.Dak. The Heart Butte and…
(Encyclopedia) Kantrowitz, AdrianKantrowitz, Adriankănˈtrəwĭtsˌ [key], 1918–2008, American surgeon, b. New York City, grad. New York Univ. (1940). The son of a physician, Kantrowitz received his M.D…
(Encyclopedia) arrhythmiaarrhythmiaārĭᵺˈmēə [key], disturbance in the rate or rhythm of the heartbeat. Various arrhythmias can be symptoms of serious heart disorders; however, they are usually of no…
(Encyclopedia) defibrillator, device that delivers an electrical shock to the heart in order to stop certain forms of rapid heart rhythm disturbances (arrhythmias). The shock changes a fibrillation…
(Encyclopedia) infarction, blockage of blood circulation to a localized area or organ of the body resulting in tissue death. Infarctions commonly occur in the spleen, kidney, lungs, brain, and heart…
(Encyclopedia) pacemaker, artificial, device used to stimulate a rhythmic heartbeat by means of electrical impulses. Implanted in the body when the heart's own electrical conduction system (natural…
(Encyclopedia) stress test or exercise electrocardiography, in medicine, a test that evaluates the performance of the heart by subjecting it to controlled amounts of physical stress. Such tests,…
(Encyclopedia) quinidinequinidinekwĭnˈĭdēnˌ [key], heart muscle relaxant used to maintain regular heart rhythm patterns. It is an alkaloid chemically similar to quinine and, like quinine, occurs…
