| MMFR | maximum midexpiratory flow rate; maximal midflow rate |
|---|---|
| MMR | mass miniature radiography; masseter muscle rigidity; maternal mortality rate; measles-mumps-rubella... |
| MPR | mannose 6-phosphate receptor; marrow production rate; massive preretinal retraction; maximum pulse r... |
| MRR | marrow release rate; maximum relation rate |
| PCR | patient contact record; phosphocreatinine; plasma clearance rate; polymerase chain reaction; post-co... |
| lethality rate | <statistics> The proportion of deaths in a population or to a specific number of the population. (18 Nov 1997) |
|---|---|
| lowest achievable emissions rate | (LAER) Used to describe air emissions control technology. A rate of emissions defined by the permitting agency. LEAR sets emission limits for non-attainment areas. (05 Dec 1998) |
| abnormal heart chamber dimensions | <radiology> Left ventricular volume overload, left ventricular hypertrophy, right ventricular volume overload, right ventricular hypertrophy, fixed subvalvular aortic stenosis, hypoplastic left/right ventricle; common ventricle, congestive cardiomyopathy (12 Dec 1998) |
| Abrams' heart reflex | A contraction of the myocardium when the skin of the precordial region is irritated. (05 Mar 2000) |
| american heart association | A voluntary organization concerned with the prevention and treatment of heart and vascular diseases. (12 Dec 1998) |
| apex of heart | The blunt extremity of the heart formed by the left ventricle. See: apex beat. Synonym: apex cordis, vertex cordis. (05 Mar 2000) |
| armored heart | Calcareous deposits in the pericardium due to subacute or chronic pericarditis. Synonym: panzerherz. (05 Mar 2000) |
| armor heart | Extensive to complete calcification (rarely ossification) of the pericardium usually producing constrictive pericarditis. (05 Mar 2000) |
| artificial heart | A mechanical pump used to replace the function of a damaged heart, either temporarily or as a permanent prosthesis. (05 Mar 2000) |
| artificial heart valve | <cardiology> A synthetic or porcine (pigskin) valve surgically placed into the heart to replace a defective or malfunctioning valve. The aortic and mitral valves are the most frequently replaced with artificial valves. (27 Sep 1997) |
| athlete's heart | A more or less loose designation for cardiac findings in healthy athletes that would be or could be abnormal in patients with disease, including atrioventricular blocks, left ventricular hypertrophy and, sometimes, benign arrhythmias and atrioventricular blocks. (05 Mar 2000) |
| athletic heart | Hypertrophy of the heart supposedly due to systematic athletic conditioning. (05 Mar 2000) |
| 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) |
| 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) |
| 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) |