| GISSI | Italian Study Group for the Prevention of Myocardial Infarction [Gruppo Italiano per lo Studio della... |
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| MIAMI | Metoprolol in myocardial infarction |
| MIRP | myocardial infarction rehabilitation program |
| MIRU | myocardial infarction research unit |
| NTMI | nontransmural myocardial infarction |
| myocardial infarct imaging | <radiology> Tc-99m pyrophosphate (PYP) 20 mCi, peak abnormality 2-3 days, often falsely negative before 2 days, abnormal for 7-10 days, mechanism: calcium influx into ischemic cells, PYP incorporated into crystalline structure, analogous to hydroxyapatite see: nuclear cardiology (12 Dec 1998) |
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| myocardial insufficiency | 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) |
| myocardial ischemia | A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (coronary arteriosclerosis), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (myocardial infarction). (12 Dec 1998) |
| myocardial necrosis | Irreversible destruction of myocardial (heart muscle) cells. (27 Sep 1997) |
| myocardial perfusion imaging | <radiology> (thallium scanning) thallium (Tl) 201, acts as potassium analog, dose 2.0 - 3.0 mCi at peak exercise, 4% of injected dose reaches myocardium, imaging: exercise (1-5 min), redistribution (3-4 hrs), views: anterior, LAO 45', left lateral, interpretation: normal, reversible abnormalitymost likely to be exercise-induced ischemia, nonreversible abnormalitymost likely to be prior myocardial infarction, reverse redistribution most likely to be normal areas wash out faster, lung activity most likely to be LV failure during exercise see also: dipyridamole test, nuclear cardiology (12 Dec 1998) |
| myocardial reperfusion | Generally, restoration of blood supply to heart tissue which is ischemic due to decrease in normal blood supply. The decrease may result from any source including atherosclerotic obstruction, narrowing of the artery, or surgical clamping. Reperfusion can be induced to treat ischemia. Methods include chemical dissolution of an occluding thrombus, administration of vasodilator drugs, angioplasty, catheterization, and artery bypass graft surgery. However, it is thought that reperfusion can itself further damage the ischemic tissue, causing myocardial reperfusion injury. (12 Dec 1998) |
| myocardial reperfusion injury | Functional, metabolic, or structural changes in ischemic heart muscle thought to result from reperfusion to the ischemic areas. Changes can be fatal to muscle cells and may include oedema with explosive cell swelling and disintegration, sarcolemma disruption, fragmentation of mitochondria, contraction band necrosis, enzyme washout, and calcium overload. Other damage may include haemorrhage and ventricular arrhythmias. One possible mechanism of damage is thought to be oxygen free radicals. Treatment currently includes the introduction of scavengers of oxygen free radicals, and injury is thought to be prevented by warm blood cardioplegic infusion prior to reperfusion. (12 Dec 1998) |
| myocardial revascularization | The restoration of blood supply to the myocardium. (12 Dec 1998) |
| myocardial rigor mortis | Irreversible contraction of the left ventricle of the heart as a complication seen in the early period of cardiopulmonary bypass and now avoided by appropriate cardioplegic solutions. Synonym: myocardial rigor mortis, stone heart. (05 Mar 2000) |
| myocardial stunning | Prolonged dysfunction of the myocardium after a brief episode of severe ischemia, with gradual return of contractile activity. It occurs frequently, both in the experimental laboratory and in clinical medicine. Since stunned myocardium occurs adjacent to necrotic tissue after prolonged coronary occlusion, many myocardial infarcts may be a mixture of necrotic and stunned tissue. (12 Dec 1998) |
| ischemic preconditioning, myocardial | Exposure of myocardial tissue to brief, repeated periods of vascular occlusion in order to render the myocardium resistant to the deleterious effects of ischemia or reperfusion. The period of pre-exposure and the number of times the tissue is exposed to ischemia and reperfusion vary, the average being 3 to 5 minutes. (12 Dec 1998) |