| heart block | <cardiology, physiology> A conduction disturbance that results in the inappropriate delay (or complete inability) of a electrical impulse, generated in the atria, to reach the ventricles (via the atrioventricular node). Clinical types are divided into first (nonserious), second and third degree (most serious) AV blocks. Some drugs may precipitate an AV block (for example clonidine, methyldopa, verapamil). A permanent pacemaker may be required for a third degree (complete) heart block. (07 Apr 1998) |
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| heart bypass, left | Diversion of the flow of blood from the pulmonary veins directly to the aorta, avoiding the left atrium and the left ventricle. This is a temporary procedure usually performed to assist other surgical procedures. (12 Dec 1998) |
| heart catheterization | Procedure which includes placement of catheter, recording of intracardiac and intravascular pressure, obtaining blood samples for chemical analysis, and cardiac output measurement, etc. Specific angiographic injection techniques are also involved. (12 Dec 1998) |
| heart conduction system | An impulse-conducting system composed of modified cardiac muscle and having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart. (12 Dec 1998) |
| heart defects, congenital | Imperfections or malformations of the heart, existing at birth. (12 Dec 1998) |
| heart-eating | Preying on the heart. Source: Websters Dictionary (01 Mar 1998) |
| heart failure | A condition where there is ineffective pumping of the heart leading to an accumulation of fluid in the lungs. Typical symptoms include shortness of breath with exertion, difficulty breathing when lying flat and leg or ankle swelling. Causes include chronic hypertension, cardiomyopathy and myocardial infarction. (27 Sep 1997) |
| heart failure cells | Macrophages in the lung during left heart failure that often carry large amounts of haemosiderin. See: siderophore. (05 Mar 2000) |
| heart failure in kids | <radiology> Primary cardiomyopathy, aortic outflow obstruction, coarctation, supravalvular aortic stenosis, valvular aortic stenosis, noncardiac lesion, asphyxia, TTN (transient tachypnea of newborn), perinatal brain damage (IVH) see also: neonatal congestive heart failure (12 Dec 1998) |
| heart hormone | A substance present in extracts of cardiac tissue that augments cardiac contraction; possibly adenosine, a catecholamine, or some non-specific stimulant present generally in tissues. Synonym: cardiac hormone, heart hormone. (05 Mar 2000) |
| heart injuries | General or unspecified injuries to the heart. (12 Dec 1998) |
| heart-lung machine | A combination blood pump and blood oxygenator used for temporary periods of time in cardiopulmonary bypass for cardiac surgery. (12 Dec 1998) |
| heart-lung transplantation | The simultaneous, or near simultaneous, transference of heart and lungs from one human or animal to another. (12 Dec 1998) |
| heart massage | Rhythmic compression of the heart by pressure applied manually over the sternum (closed heart massage) or directly to the heart through an opening in the chest wall (open heart massage). It is done to reinstate and maintain circulation. (12 Dec 1998) |
| heart murmur | A finding on physical examination of the heart that can, in some cases, indicate the presence of cardiac disease. Murmurs result from vibrations set up in the bloodstream and the surrounding heart and great vessels as the result of turbulent flow. (27 Sep 1997) |