Electrocardiography, cardioenzymes and myocardial imaging to detect perioperative myocardial infarction.
Serial electrocardiography, technetium-99m pyrophosphate scintigraphy and measurement of myocardial creatine kinase (CK2) and lactic dehydrogenase isoenzyme activity (specifically the LD1 to LD2 ratio) were evaluated prospectively in 26 patients who underwent aortocoronary bypass grafting and 11 patients who underwent valvular or other thoracic surgery, as methods of diagnosing perioperative myocardial infarction. Of the 26 patients who had aorto coronary bypass grafting, 7 (group 1) had myocardial infarction perioperatively; of these, only 2 had positive results from all four diagnostic tests. The other 19 patients (group 2) had no perioperative myocardial infarction and the only diagnostic method yielding positive results was the LD1 to LD2 ratio, in 7 of the 19. In the 11 patients who did not undergo aortocoronary bypass grafting (group 3), only 1 patient had myocardial infarction perioperatively; results from the measurement of CK2 isoenzyme activity and LD1 to LD2 ratio were positive while electrocardiography and 99mTc pyrophosphate scintigraphy yielded negative results. The respective sensitivity (%) and specificity (%) of the four diagnostic methods were as follows: electrocardiography: 38, 100; 99mTc pyrophosphate scintigraphy: 88, 100; LD1 to LD2 ratio: 100, 68; CK2: 38, 100. When the CK2 criterion was redefined, using patients in group 2 as controls, the sensitivity and specificity of this method became 100 and 90 respectively. The authors conclude that 99MTc pyrophosphate scintigraphy and measurement of myocardial creatine kinase isoenzyme are of comparable value and are the most reliable indicators of perioperative myocardial infarction.
D001026:Coronary Artery Bypass; D003402:Creatine Kinase / Q000032:analysis*; D011756:Diphosphates; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D009206:Myocardium / Q000201:enzymology; D011183:Postoperative Complications; D011184:Postoperative Period; D011446:Prospective Studies; D011877:Radionuclide Imaging; D013667:Technetium; D016698:Technetium Tc 99m Pyrophosphate
D011756:Diphosphates; D007527:Isoenzymes; D016698:Technetium Tc 99m Pyrophosphate; D013667:Technetium; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase