Delayed effect of streptokinase on left ventricular function after acute myocardial infarction assessed by equilibrium gated radionuclide angiocardiography

A blind comparative study was conducted on 80 consecutive patients who were given Streptokinase (SK) or placebo between 3 and 6 hours after the onset of acute myocardial infarction (AMI). Left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR) and regional wall motion (RWM) were evaluated by equilibrium gated radionuclide angiocardiography (EGRA) at 3-5 weeks and 6 months after the onset of AMI. In the anterior AMI SK-group, the mean LVEF values rose from 0.37 at one month to 0.43 at six months, PER (end-diastolic volumes per second) from 1.76 to 2.00, and PFR (end-diastolic volumes per second) from 1.46 to 1.75 (p = 0.01, p < 0.05, and p < 0.05, respectively). In the anterior non-SK group no improvement was seen in any of the LV function parameters. Only a slight improvement was observed in the inferior AMI group, with no significant difference between the treated and non-treated patients. The regional wall motion analysis was in agreement with the global function data. In conclusion, SK treatment given between three and six hours after the onset of anterior AMI may result in some improvement in LV function, which becomes fully appreciable only after the complete resolution of stunning, i.e. after more than one month.