Myocardial Infarction Related to Coronary Artery Bypass Graft Surgery

Abstract

SUMMARY Fifty consecutive patients undergoing coronary artery bypass grafting for chronic stable angina were assessed by serial electrocardiography, preoperative and postoperative myocardial scanning with technetium-99m pyrophosphate, gated radionuclide ventriculography, and serial measurement of creatine kinase, aspartate aminotransferase, urea stable lactic dehydrogenase, and creatine kinase isoenzyme (MB) to assess the incidence of perioperative myocardial infarction and identify the most appropriate diagnostic techniques. The correlation between myocardial scanning and the measurement of peak enzyme and isoenzyme activity was excellent in the diagnosis of perioperative infarction, although electrocardiography proved less helpful. There appeared to be no advantage in measuring creatine kinase MB rather than the more routinely measured enzymes. There were two deaths and evidence of myocardial infarction in five other patients, an incidence of 14%. Perioperative infarction was associated with a significant reduction in resting ejection fraction in two cases. In those patients without evidence of perioperative infarction the mean increase in ejection fraction of 7.80/o was statistically significant.Myocardial infarction related to coronary artery bypass graft surgery is associated with increased mortality and morbidity and accounts for most deaths perioperatively and within the first month of operation.' The incidence of this complication is difficult to estimate, and figures of 4-40% have been reported.2-4 The varying incidence can be attributed to variations in operative expertise, techniques of myocardial protection, case selection, and particularly to the diagnostic indices of myocardial infarction applied in different series. [5][6][7] The assessment of chest pain and interpretation of the electrocardiogram in the diagnosis of myocardial infarction after cardiac surgery are difficult.8-'0 An increase in the activity of enzymes, including the relaRequests for reprints to Dr

Creatine Kinase and the Diagnosis of Myocardial Infarction

“…3) : 1. In the uncomplicated case, without infarction, the rises in serum CK and CK-MB tend to be smaller than in patients who have had pen-operative infarction [61,62]. Thus, it is rare for CK-MB to exceed 50 U/liter in the average uncomplicated case.…”

“…To do this, additional blood sampling is required, for instance at the end of the operation and at 4,8,12, and 24 h post-operatively. The evidence provided by serum enzyme measurement, especially CK and CK-MB, is particularly important as the ECG is unreliable in these patients [61].…”

Ressonância magnética vs cintilografia com pirofosfato marcado com tecnécio-99m para a detecção de necrose miocárdica perioperatória

“…Only the areas of delayed myocardial contrast enhancement (necrosis / fibrosis) with signal intensity greater than two standard deviations above the mean value of myocardial signal intensity in a remote area considered normal according to a methodology described elsewhere 15 were delimited. The 1.05 g/cm 3 value of myocardial density was used for the calculation of the infarcted mass. POMI was defined as the finding of a new area of delayed myocardial contrast enhancement in the postoperative test that was not present in the imaging test performed before surgery.…”

“…Despite the advances in surgical techniques and intensive care, perioperative myocardial infarction (POMI) is still a complication of coronary artery bypass grafting (CABG), with a potential prognostic impact [1][2][3][4][5] . Among the tests used for its diagnosis, technetium-99m pyrophosphate myocardial scintigraphy (MS) stands out as a noninvasive method able to visualize areas of myocardial necrosis 6 .…”

Detecção de infarto do miocárdio perioperatório pela ressonância magnética em pacientes submetidos a cirurgia de revascularização miocárdica

“…Apesar dos avanços nas técnicas cirúrgicas e cuidados intensivos, o infarto do miocárdio perioperatório (IMPO) ainda é uma complicação observada após a cirurgia de revascularização miocárdica, com potencial impacto prognóstico [1][2][3][4][5] . Na sua gênese, vários mecanismos foram sugeridos, tais como revascularização incompleta, doença coronária aterosclerótica difusa e distal, espasmo coronariano, embolia, trombose de artérias nativas ou de enxertos, problemas técnicos com as anastomoses dos enxertos, proteção miocárdica inadequada, aumento da demanda miocárdica de oxigênio e instabilidade hemodinâmica.…”