Enzymatic and Immunogenic Changes of Myocardial Infarction

Diagnosis of myocardial infarction is very important in a patient with chest pain. Chest pain is not always present or it may be from other causes rather than myocardial infarction. Q wave is present in 30] of infarction. ST,T wave changes are present in all myocardial infarctions, but these changes also are present in myocardial ischernia.  For these reasons diagnosis of myocardial infarction can be done with enzymatic changes in the serum. CPK, MB and LDH isoenzymes are specific for myocardial injury. Serum Glutamic Oxalacetic Transaminase.This enzyme will rise 6 hours after infarction  and peak level reach at 12-24 hours and gradually will return to normal within 6-7 days.  Serum Lactic Dehydrogenase. LDH increases 10 hours after  infarction and maximum level reached in 48-72 hours. LDH returns to normal after 10 days.  There are five kinds of LDH, which can be separated with Electrophoresis techinc. LDHl, LDH2 are the fast part of enzyme and is specific for myocardial injury. LDHl and LDH2 are resistant to 65 centigrade tempera­ture for 30 minutes and by this technic also can be measured.  Creatinine phosphokinase. This enzyme increase in  myocardial infarction 6 to 8 hours post infarction. maximum level reach at 24 hours and return to normal at 36 hours after infarction. CPK isoenzyme is very specific for myocardial injury.  This part of enzym is called CPK, MB. Relation of enzyme level and Prognosis of myocardial infarction Prognosis of myocardial infarction has direct relation to CPK and SGOT level. 40% of 125 patients with myocardial, whom died, enzymes were five times normal. 81).' of these patients had arrythrnia, enzymes level were 4 times normal.  Myocardial infarction size can be estimated with following formola CPK-22x myocardial infarction size-318 if myocardial infarction size is more 68 grams most of these patients will die or complicate with congestive heart failure.  Antlmyocardial Antibodies estimated with antinuclear antibodies, complement fixation, immunoflurescent and hemagglutination tech­nics.