| MLS | mean lifespan; median life span; median longitudinal section; microphthalmia-linear skin defects [sy... |
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| Mz | longitudinal magnetization |
| OALL | ossification of anterior longitudinal ligament |
| OPLL | ossification of posterior longitudinal ligament |
| PLL | peripheral light loss; phase-locked loop; poly-L-lysine; pressure length loop; posterior longitudina... |
| atrium of heart | The upper chamber of each half of the heart. Synonym: atrium cordis, atrium. Left atrium of heart, atrium of the left side of the heart which receives the blood from the pulmonary veins. Synonym: atrium sinistrum cordis, atrium pulmonale. (05 Mar 2000) |
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| backward heart failure | A concept (formerly considered mutually exclusive of forward heart failure) that maintains that the phenomena of congestive heart failure result from passive engorgement of the veins caused by a "backward" rise in pressure proximal to the failing cardiac chambers. Compare: forward heart failure. (05 Mar 2000) |
| baseline foetal heart rate | <paediatrics> The average heart rate for a particular foetus during the diastolic phase of uterine contractions. (05 Mar 2000) |
| baseline variability of foetal heart rate | The beat-to-beat changes in foetal heart rate as recorded on a graph. (05 Mar 2000) |
| base of heart | That part of the heart that lies opposite the apex, formed mainly by the left atrium but to a small extent by the posterior part of the right atrium; it is directed backward and to the right and is separated from the vertebral column by the oesophagus and aorta. Synonym: basis cordis. (05 Mar 2000) |
| beer heart | <cardiology, pathology> A weakness of the cardiac muscle which is seen in some chronic alcoholics, may be related to a thiamin deficiency or occur for unknown reasons. Origin: Gr. Pathos = disease (27 Sep 1997) |
| beriberi heart | Heart disease due to thiamine deficiency that may be epidemic or sporadic as characterised by cardiac metabolic damage and myocardial failure, often of the "high output" type, with oedema (except in "dry" beri) and polyneuritis. The term is derived from Singhalese, "I am unable." (05 Mar 2000) |
| biopsy, heart | <investigation, procedure, surgery> A procedure which involves the removal of a small specimen of cardiac muscle tissue for microscopic analysis. This is generally performed at the same time as a cardiac catheterisation or as a very similar, yet separate, procedure. A small piece of heart tissue is taken via a small forceps inserted into the cardiac catheter site (usually threaded through a vein in the neck). This test may reveal the cause of a cardiomyopathy, myocarditis, amyloidosis or a heart transplant rejection. (21 Mar 1998) |
| bony heart | The presence of extensive calcareous patches in the pericardium and walls of the heart, some of which chronically develop bony changes. (05 Mar 2000) |
| box-like heart | <radiology> Ebstein's anomaly, massive cardiomegaly, primarily RA enlargement (12 Dec 1998) |
| brain-heart infusion agar | A medium used for the isolation of fastidious microorganisms, especially fungi. (05 Mar 2000) |
| carcinoid heart disease | Cardiac manifestation of malignant carcinoid syndrome. It is a unique form of fibrosis involving the endocardium, primarily of the right heart. The fibrous deposits tend to cause constriction of the tricuspid and pulmonary valves. (12 Dec 1998) |
| machine, heart-lung | A machine that does the work both of the heart (pump blood) and the lungs (oxygenate the blood). Used, for example, in open heart surgery. Blood returning to the heart is diverted through the machine before returning it to the arterial circulation. Also called a pump-oxygenator. (12 Dec 1998) |
| valvular heart disease | A general term that applies to any abnormality of one of the heart valves, tricuspid, mitral, aortic or pulmonic valves. (27 Sep 1997) |
| rate, heart | Number of heart beats per minute. The normal resting adult heart beats regularly at an average rate of 60 times per minute. (young children's hearts beat faster). The speed of the heartbeat (heart rate) is governed by the speed of electrical signals from the pacemaker of the heart, the sa node, located in the right atrium (upper chamber of the heart). The electrical signals from the sa node travel across the atria and cause these two upper heart chambers to contract, delivering blood into the lower heart chambers, the ventricles. The electrical signals then pass through the av node to reach the ventricles. Electrical signals reaching the ventricles cause these chambers to contract, pumping blood to the rest of the body, generating the pulse. During rest, the speed of electrical signals originating from the sa node is slow, so the heart beats slowly. During exercise or excitement, the speed of signals from the sa node increases, and the heartbeat quickens. (12 Dec 1998) |