Objective: To observe the relation of ST-segment elevation pattern of electrocardiogram (ECG) recorded in acute phase of anterior wall acute myocardial infarction (AMI) to short-term prognosis.
Methods: Sixty-two patients with first anterior wall AMI were divided into 3 groups according to ST-segment elevation pattern in lead V3 of a 12-lead ECG at admission. Patients in group A (n=18) were characterized by concave type of ST-segment elevation, group B (n=27) by straight type and group C (n=17) by convex type. The peak value of serum creatine phosphate kinase (CPK) and left ventricular ejection fraction (LVEF) were measured. The incidence of serious complications (including malignant arrhythmia, left ventricular dysfunction and cardiogenic shock) and mortality within the initial 4 weeks of hospitalization were recorded.
Results: The median value of peak CPK of the 3 groups was 2 014.4, 4 486.8 and 5 826.9 IU/L respectively, and the peak value of CPK in group A was much lower than that in groups B and C ( D<0.05 and P<0.01, respectively). LVEF measured by echocardiogram within 14 d after myocardial infarction were 61.2%, 48.6% and 38.7% respectively, showing significant difference between groups A and B and between groups B and C (P<0.05) as well as between group A and C (P<0.01). The incidences of serious complications and mortality within 4 weeks after AMI in group A were much lower than those in groups B and C (P<0.05), but there was no significant difference between groups B and C ( D>0.05).
Conclusion: The shape of ST-segment elevation in lead V3 of a 12-lead ECG in acute phase of anterior wall AMI may reflect the severity of myocardial ischemic injury, and convex type of ST-segment elevation in lead V3 in acute phase often indicate poor short-term prognosis.