[Assessment of regional quantitative analysis by ECG-gated myocardial SPECT after coronary artery bypass surgery]
T Higuchi1, J Taki, K Nakajima
1Department of Nuclear Medicine, School of Medicine, Kanazawa University.
Insights
Coronary artery bypass surgery (CABG) can alter regional function assessments. Systolic wall thickening (WT) is a more reliable measure than regional ejection fraction (rEF) or wall motion (WM) after CABG.
Area of Science:
- Cardiovascular Imaging
- Nuclear Cardiology
- Cardiac Surgery
Background:
- Coronary artery bypass surgery (CABG) is a common intervention for coronary artery disease.
- Assessing regional myocardial function after CABG is crucial for patient management.
- ECG-gated myocardial SPECT (G-SPECT) is a widely used imaging modality.
Purpose of the Study:
- To evaluate the impact of CABG on quantitative regional myocardial function parameters derived from G-SPECT.
- To determine the reliability of different G-SPECT parameters in assessing myocardial function post-CABG.
Main Methods:
- Nineteen patients with coronary artery disease underwent G-SPECT before and 1 month after uncomplicated CABG.
- 99mTc-MIBI was used for rest myocardial perfusion imaging.
- Quantitative gated SPECT (QGS) software was employed to assess regional ejection fraction (rEF), wall motion (WM), systolic wall thickening (WT), and % tracer uptake in 16 myocardial segments.
Main Results:
- Percent tracer uptake and systolic wall thickening (WT) showed no significant change after CABG.
- A significant decrease in regional ejection fraction (rEF) and wall motion (WM) was observed, particularly in the septum.
- These changes suggest a potential for pseudoparadoxical asynergy post-CABG.
Conclusions:
- Standard G-SPECT parameters like rEF and WM may be influenced by factors other than ischemia after uncomplicated CABG.
- Systolic wall thickening (WT) appears to be a more robust parameter for evaluating regional myocardial function post-CABG.
- WT may be the preferred parameter for assessing regional function after CABG using G-SPECT.
Purpose:
ECG-gated myocardial SPECT (G-SPECT) was performed before and after coronary artery bypass surgery (CABG) to investigate how this operation would affect the assessment of regional quantitative analyses.
Methods:
Nineteen patients with coronary artery disease underwent G-SPECT before and 1 month after uncomplicated CABG. 99mTc-MIBI 740 MBq was injected at rest, then G-SPECT was performed 60 min later. Regional ejection fraction (rEF), wall motion (WM), systolic wall thickening (WT) and % tracer uptake were evaluated by quantitative gated SPECT program (QGS). Parameters were obtained quantitatively in 16 segments based on the functional bull's eye map.
Results:
Percent tracer uptake increased in septum from 75 +/- 11% to 78 +/- 11% (p < 0.001), while WT did not change (40 +/- 19% to 41 +/- 20%) after CABG. However, in septum rEF decreased from 17 +/- 13% to 6 +/- 9% (p < 0.001) and WM decreased in septum from 1.6 +/- 1.1 mm to 0.6 +/- 0.9 mm (p < 0.001).
Conclusion:
Significant reduction of rEF and WM despite of no deterioration of WT and % tracer uptake suggested that rEF and WM were affected by pseudoparadoxical asynergy after uncomplicated CABG. For the evaluation of regional function after CABG by G-SPECT, WT might be the preferred parameter.
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