Biochemical features in patients with their first acute inferior myocardial infarction

Sixty eight patients with their first acute inferior myocardial infarction were studied within 24 h of the onset of chest pain by vectorcardiography and biochemical indicators. Patients were divided into three groups according to the vectorcardiographic findings: Group 1 (31 patients with inferior myocardial infarction); Group 2 (26 patients with inferior myocardial infarction and right ventricular involvement); and Group 3 (11 patients with inferior-posterior infarction). Biochemical studies showed that the tendency for the magnitude of enzyme release varied with the site inferior-posterior > inferior+right ventricular > inferior groups. However, the differences between inferior and inferior plus right-ventricular groups were not significant. This suggests that the left ventricle dominates enzyme release regardless, with or without right ventricular involvement in patients with acute inferior myocardial infarction. When the enzyme levels in inferior and inferior-posterior myocardial infarction are compared, the HBDH and CK-MB were significantly higher (2P < 0.02 and 2P < 0.05 respectively). This confirms that when the vectorcardiographic QRS loop changes are large, more enzyme is released during acute myocardial infarction.