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Evolution of left ventricular function after intracoronary thrombolysis for acute myocardial infarction
W G Schmidt1, F H Sheehan, R von Essen
1Department of Internal Medicine I, Rheinisch Westfaelische Technische Hochschule, Aachen, West Germany.
Insights
Left ventricular function initially worsens after acute myocardial infarction (AMI) treatment due to compensatory hyperkinesis regression. Full recovery of impaired heart muscle takes longer than three days, impacting ejection fraction and wall motion.
Area of Science:
- Cardiology
- Cardiovascular Research
- Interventional Cardiology
Background:
- Acute myocardial infarction (AMI) poses significant risks to left ventricular (LV) function.
- Intracoronary streptokinase therapy is a treatment option for AMI.
- Understanding the temporal dynamics of LV function post-treatment is crucial for patient outcomes.
Purpose of the Study:
- To assess the temporal evolution of left ventricular (LV) function after intracoronary streptokinase therapy in patients with acute myocardial infarction (AMI).
- To correlate changes in LV function with reperfusion status and wall motion abnormalities.
Main Methods:
- Retrospective analysis of 264 patients undergoing intracoronary streptokinase for AMI.
- Serial angiography performed immediately, at 3 days, and 6 months post-treatment.
- Left ventricular (LV) wall motion assessed using the centerline method; ejection fraction calculated.
Main Results:
- Sustained reperfusion showed an initial decrease in ejection fraction at 3 days, followed by recovery by 6 months.
- Hyperkinesis in non-infarcted walls regressed by 3 days, with delayed recovery in infarct regions.
- Patients without reperfusion experienced a more severe ejection fraction decrease and limited functional recovery.
Conclusions:
- Full recovery of ischemically impaired myocardium exceeds 3 days post-AMI.
- Early LV function deterioration can result from compensatory hyperkinesis regression, not necessarily infarct extension.
- Reperfusion status significantly influences long-term LV functional recovery after AMI treatment.
Abstract:
The temporal evolution of left ventricular (LV) function after intracoronary streptokinase therapy for acute myocardial infarction (AMI) was assessed from the data of 264 patients who had complete occlusion of either the left anterior descending or the right coronary artery before treatment. Angiography was performed immediately, and at 3 days and 6 months after AMI in 91%, 71% and 47% of the study group, respectively. Wall motion was measured by the centerline method. In patients with sustained reperfusion, the ejection fraction decreased at 3 days (delta = -2.0 +/- 9.9%, n = 134, p = 0.02) and recovered later (from 54 +/- 12% acutely to 57 +/- 12% at 6 months, n = 82, p less than 0.05). These changes in global function were associated with a marked regression in hyperkinesis in the noninfarcted wall by 3 days, and delayed recovery of wall motion in the infarct region (delta = 0.2 +/- 0.9 at 3 days, p = 0.055; 1.0 +/- 1.2 at 6 months, p less than 0.001). Patients without reperfusion or with reocclusion had a more severe decrease in ejection fraction at 3 days, and little or no subsequent functional recovery. The length of the hypokinetic segment increased significantly by 3 days but subsequently diminished to slightly less than the acute value. It is concluded that full recovery of ischemically impaired myocardium takes greater than 3 days, but compensatory hyperkinesis regresses earlier so that global LV function deteriorates by the third day. Variability or deterioration of LV function early after AMI need not be due to infarct extension; it can reflect regression of hyperkinesis in the noninfarcted region.