[The clinical importance of persistent elevation of electrocardiographic ST segment in acute myocardial infarction patients after reperfusion therapy].

OBJECTIVE

To observe the clinical importance of persistent elevation of electrocardiographic ST segment in acute myocardial infarction (AMI) patients receiving direct percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Thirty patients with a first AMI successfully treated with direct coronary angioplasty were selected. The extent of the ST segment elevation and resolution in electrocardiograms on admission and one hour after direct PTCA was analyzed. All the patients were divided into two groups according to the extent of ST segment elevation and resolution. Group A: resolution of ST segment elevation >or=50%, n = 19; Group B: resolution of ST segments elevation < 50%, n = 11. Low-dose dobutamine stress echocardiogram was taken at (7 +/- 2) days after AMI and echocardiogram checked at 1, 2 and 3 months after AMI.

RESULTS

Left ventricular ejection fraction (LVEF) in group A was higher than that in group B at the first week and the first, second and third month after AMI. Aortic blood peak acceleration, cardiac output and cardiac output index of group A were all significantly higher than those in group B at stress. Global wall motion score index (GWMSI) and infarct-zone wall motion score index (IWMSI) in group A were smaller than those in group B at baseline and stress. GWMSI in group A was smaller than that in group B at 1, 2 and 3 months after AMI. There was no significant difference of IWMSI between group A and group B at 1 and 2 months after AMI. IWMSI in group A was smaller than that in group B at the third month after AMI.

CONCLUSIONS

The patients in group B had lower left ventricular contractile function and contractile reserve function and less recovery of infarct-zone wall motion than that in group A.