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Assessment of function of contractile segments in patients with left ventricular aneurysms by quantitative first pass
Insights
First pass radionuclide ventriculography accurately estimates ejection fraction of the contractile segment (EFCS) in patients with left ventricular aneurysms. This measurement is crucial for predicting surgical outcomes and understanding cardiac function responses.
Area of Science:
- Cardiology
- Nuclear Medicine
- Cardiovascular Imaging
Background:
- Left ventricular aneurysms are a complication of myocardial infarction.
- Accurate assessment of contractile segment function is vital for patient management.
Purpose of the Study:
- To evaluate the accuracy of first pass radionuclide ventriculography in measuring the ejection fraction of the contractile segment (EFCS).
- To assess the relationship between EFCS and stroke volume index during rest and exercise.
- To determine the effect of isosorbide dinitrate on EFCS during exercise.
Main Methods:
- Contrast angiography and first pass radionuclide ventriculography were performed in 13 patients.
- Ejection fraction of the contractile segment (EFCS) was measured using a double hemishperoid model.
- Thermodilution cardiac outputs and radionuclide ventriculography were performed simultaneously at rest and during exercise, with and without isosorbide dinitrate.
Main Results:
- EFCS measurements from contrast angiography and radionuclide ventriculography showed close correlation.
- A monotonic relationship was observed between EFCS and stroke volume index at rest.
- Changes in EFCS during exercise paralleled changes in total left ventricular ejection fraction and stroke volume index.
- Isosorbide dinitrate improved left ventricular ejection fraction and EFCS during exercise in most patients.
Conclusions:
- First pass radionuclide ventriculography is a reliable method for estimating EFCS in patients with left ventricular aneurysms.
- EFCS is a significant predictor of response to aneurysmectomy.
- Exercise-induced changes in EFCS reflect overall left ventricular performance, and vasodilators may enhance contractile function.
Abstract:
Thirteen patients with left ventricular aneurysms complicating myocardial infarction were studied by contrast angiography and by first pass radionuclide ventriculography. The ejection fraction of the contractile segment (EFCS) was measured from both studies using a double hemishperoid model, and the values correlated closely. There was a monotonic relation between EFCS and stroke volume index measured from thermodilution cardiac outputs carried out simultaneously with the radionuclide study. When radionuclide ventriculography was performed at submaximal supine exercise, changes in EFCS paralleled changes in the total left ventricular ejection fraction in 10 of the 13 cases. In nine patients, changes in EFCS paralleled changes in stroke volume index and the relation between EFCS and stroke volume index was maintained at exercise. After administration of the vasodilator isosorbide dinitrate to 12 patients, repeat exercise radionuclide ventriculography showed an improvement in left ventricular ejection fraction and in eight patients EFCS improved. First pass radionuclide ventriculography can accurately estimate EFCS, which may be an important factor in predicting the likely response to aneurysmectomy. Changes in EFCS on exercise are reflected in changes in total left ventricular ejection fraction and stroke volume index. Isosorbide dinitrate may improve contractile segment function on exercise.