Detection of residual wall motion after sustained myocardial infarction by gated 99Tcm-tetrofosmin SPECT: a
F F Wahba1, C D Bavelaar-Croon, L H Baur
1Department of Cardiology, Leiden University Medical Center, The Netherlands. e.e.van_der_wall@lumc.nl
Insights
Gated single photon emission computed tomography (SPECT) reliably assesses heart wall motion after myocardial infarction. This technique helps identify viable heart muscle in areas with poor blood flow, aiding revascularization decisions.
Area of Science:
- Cardiology
- Nuclear Medicine
- Medical Imaging
Background:
- Assessing myocardial viability is crucial for guiding revascularization in post-myocardial infarction (MI) patients.
- Gated single photon emission computed tomography (SPECT) combines perfusion and functional data, offering a comprehensive view of myocardial health.
Purpose of the Study:
- To evaluate the agreement between gated SPECT and echocardiography in assessing left ventricular wall motion.
- To compare the concordance of myocardial perfusion and wall motion analysis using both gated SPECT and echocardiography.
Main Methods:
- 25 patients with previous MI underwent gated SPECT (99Tcm-tetrofosmin) and echocardiography within 2 weeks.
- The left ventricle was divided into seven regions for both imaging modalities, totaling 175 regions for analysis.
- Wall motion and perfusion data were compared between gated SPECT and echocardiography.
Main Results:
- High agreement (80%) was found in wall motion scoring between gated SPECT and echocardiography.
- Agreement between myocardial perfusion and wall motion was 82% for gated SPECT and 76% for echocardiography.
- 34% of regions with diminished perfusion showed preserved wall motion, suggesting residual viability.
Conclusions:
- Gated SPECT is a reliable tool for assessing regional wall motion in post-MI patients.
- Gated SPECT can identify residual myocardial viability in malperfused regions by detecting preserved wall motion despite fixed perfusion defects.
Abstract:
The differentiation of residual viability from necrotic myocardium in patients with a previously sustained myocardial infarction is important in deciding indications for revascularization. Myocardial viability can be assessed by studying perfusion and regional wall motion. With gated single photon emission computed tomography (SPECT), it is possible to augment SPECT perfusion data with ventricular functional data both at a global and regional level. The aim of the study was to analyse the concordance between wall motion score derived by gated SPECT and echocardiography. Furthermore, the agreement between myocardial perfusion and left ventricular wall motion was analysed with both techniques. We studied a homogenous group of 25 consecutive patients with a previous myocardial infarction (MI) using both gated SPECT 99Tcm-tetrofosmin myocardial perfusion imaging and two-dimensional echocardiography. Echocardiography was performed within 2 weeks of the gated SPECT study. Both for gated SPECT and for echocardiography the left ventricle was divided into seven regions per patient. For comparison, the gated SPECT regions were matched to the echocardiographic regions, resulting in a total of 175 regions. Prevalence of abnormal wall motion (akinetic or dyskinetic) was 23% (39/171) for echocardiography and 21% (36/175) for gated SPECT (P = NS). There was a high agreement in wall motion score between echocardiography and gated SPECT of 80% (136/171). The agreement between myocardial perfusion and myocardial wall motion was 82% (143/175) for gated SPECT and 76% (130/171) for echocardiography (P = NS). Nineteen (34%) of the 56 regions with severely diminished or absent myocardial perfusion showed normal or hypokinetic wall motion both by gated SPECT and echocardiography suggesting residual myocardial viability in malperfused regions. Our results suggest that, gated SPECT imaging is a reliable tool for the assessment of regional wall motion in post myocardial infarction patients. Furthermore, in patients with a previous myocardial infarction gated SPECT imaging has the potential to detect preserved wall motion in regions with fixed perfusion defects, which might be indicative of residual myocardial viability.
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