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Myocardial viability: impact on left ventricular dilatation after acute myocardial infarction
F Nijland1, O Kamp, P M J Verhorst
1Department of Cardiology and Institute for Cardiovascular Research, Free University Hospital, PO Box 7057, 1007 MB Amsterdam, Netherlands. cardiol@azvu.nl
Insights
Myocardial viability detected by low dose dobutamine echocardiography predicts preserved left ventricular size after acute myocardial infarction. Absence of viability leads to ventricular dilatation, especially in large infarcts.
Area of Science:
- Cardiology
- Echocardiography
- Myocardial Infarction
Background:
- Acute myocardial infarction can lead to left ventricular remodeling and dilatation.
- Assessing myocardial viability is crucial for predicting long-term outcomes.
- Low dose dobutamine echocardiography is a tool to detect myocardial viability.
Purpose of the Study:
- To determine if myocardial viability, identified by low dose dobutamine echocardiography, influences left ventricular dilatation post-acute myocardial infarction.
- To investigate the association between myocardial viability and changes in left ventricular dimensions.
Main Methods:
- 107 patients with acute myocardial infarction underwent low dose dobutamine echocardiography.
- Patients were categorized into groups based on the presence or absence of myocardial viability.
- Echocardiography was repeated at three months to assess left ventricular dimensions.
Main Results:
- Patients with myocardial viability maintained stable left ventricular end-diastolic volume index (EDVI) and reduced end-systolic volume index (ESVI).
- Patients without viability showed significant increases in both EDVI and ESVI.
- Ventricular dilatation was observed primarily in patients with large infarcts and without myocardial viability.
Conclusions:
- The presence of myocardial viability early after acute myocardial infarction is linked to preserved left ventricular size.
- Absence of viability is a significant predictor of left ventricular dilatation, particularly in cases of large infarcts.
Objective:
To evaluate whether the presence of viable myocardium, detected by low dose dobutamine echocardiography, limits the likelihood of left ventricular dilatation in patients with acute myocardial infarction.
Patients:
107 patients were studied by low dose dobutamine echocardiography at (mean (SD)) 3 (1) days after acute myocardial infarction. Cross sectional echocardiography was repeated three months later. Patients were divided in two groups based on the presence (n = 47) or absence (n = 60) of myocardial viability.
Results:
Baseline characteristics were comparable between the two groups, except for infarct location. Left ventricular end diastolic volume index (EDVI) was stable in patients with viability, but end systolic volume index (ESVI) decreased significantly (p = 0.006). Patients without viability had a significant increase in both EDVI (p < 0.0001) and ESVI (p = 0.0007). Subgroup analysis in patients with small and large infarcts (peak creatine kinase < or = 1000 v > 1000 IU/l) showed that ventricular dilatation occurred only in patients with large infarcts without viability. This resulted in larger ESVI values at three months in that group compared with patients with large infarcts plus viability (p < 0.05). Multivariate regression analysis identified myocardial viability as an independent predictor of left ventricular dilatation, along with wall motion score index on low dose dobutamine echocardiography and the number of pathological Q waves.
Conclusions:
The presence of viability early after acute myocardial infarction is associated with preservation of left ventricular size, whereas the absence of viability results in ventricular dilatation, particularly in large infarcts.