The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook Columbia Gazetteer American Heritage Coll.
Infarctions commonly occur in the spleen , kidney, lungs , brain , and heart .
The acute emergency known as myocardial infarction, or heart attack, is usually caused by a blockage in one of the coronary arteries that supply blood to the heart muscle. The seriousness of the infarction is dependent upon the amount of heart muscle affected, how long the area is deprived of blood, and whether it affects the natural pacemaker of the heart, setting off arrhythmias such as ventricular fibrillation. Confirmation of myocardial infarction is made by electrocardiography and measurement of elevations of white blood cells and certain enzymes. The healing of an infarction occurs through replacement of the dead tissue by scar tissue. 1 See also coronary artery disease .