System In Acute Myocardial Infarction Research Articles

Comparative study of paracoagulation tests in acute myocardial infarction

Ethanol, -naphthol (test for "fibrinogen B") and protamine sulfate tests, performed simultaneously in the blood plasma of patients with acute myocardial infarction, showed a high degree of correlation with each other, but they differed in sensitivity: ethanol -naphthol protamine sulfate. Heparin did not distort the results of the ethanol and -naphthol tests, while the protamine sulfate test results strongly depended on the presence of heparin. The formation of a granular precipitate is not a positive protamine sulfate test and indicates hyperheparinemia. The ethanol test on the basis of data can be recommended to monitor the state of the hemocoagulation system in acute myocardial infarction, including the period of heparin therapy.

The cardiac conduction system in acute myocardial infarction. A clinicopathological correlation.

Summary: Detailed autopsy examination of the cardiac conduction system was carried out in 30 patients with and without heart block complicating acute myocardial infarction (AMI), and the hearts of another 30 patients who died from non‐cardiac disease were used as controls in the interpretation of the histological changes. Fibrosis of the conduction tissue was prevalent in both the AMI and control patients; and among the AMI patients, appeared to be unrelated to whether there was a conduction defect. Patients with anterior infarcts more commonly had intraventricular block and infarction of the bundle branches with sparing of the proximal conduction tissue. Patients with posterior infarcts were more likely to have atrioventricular (AV) block preceded by Wenckebach phenomenon but necrosis of AV node was relatively uncommon. The His bundle electrogram was a useful clinical investigation and correlated well with the histopathology of the conduction tissue in determining the site of heart block.

Anatomic studies of the cardiac conducting system in acute myocardial infarction

The anatomic changes in the cardiac conducting fibers were studied in 20 patients who developed atrioventricular and intraventricular conduction disturbances in the course of acute myocardial infarction. In 12 of these cases there was no apparent morphologic injury to the conducting fibers, and in 5 of 8 cases with focal necrosis of the conducting tissue the involvement was of relatively minor severity. These facts correlate with the transient nature of the conduction defect in most survivors.

The Conduction System in Acute Myocardial Infarction Complicated by Heart Block

Detailed histological examination of the conduction system in 29 cases of acute myocardial infarction complicated by heart block has been carried out. In 24 cases posterior infarction was present and occlusion had occurred in the artery from which the blood supply to the A-V node was ultimately derived. In these cases major structural damage to the conduction system was rare, but when present, involved the bundle branches. A-V block in posterior infarction is therefore usually due to hypoxia or other reversible factors rather than structural damage to the conduction system. These findings are consistent with the high incidence of transient heart block in survivors. In five cases anterior infarction alone was present. The blood supply of the A-V node was not compromised, but massive infarction had caused major damage to both bundle branches. Since major structural damage to the conduction system is uncommon in myocardial infarction, only a minority of survivors will have permanent heart block. In those cases in which there is extensive damage to the bundle branches there is a risk of high mortality and permanent block particularly when the infarct is anteroseptal.

The coronary circulation and conduction system in acute myocardial infarction

The coronary circulation and conduction system in acute myocardial infarction