scholarly journals RELATIONSHIP BETWEEN FRONTAL QRS-T ANGLE AND MYOCARDIAL PERFUSION DEFECT (MPD) FROM SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT) IN PATIENTS WITH PRIOR MYOCARDIAL INFARCTION

2021 ◽  
Vol 7 (2) ◽  
pp. 5
Author(s):  
Vitri Alya
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Perfusion ◽  
Perfusion Defect ◽  
Single Photon ◽  
Photon Emission ◽  
Previous History ◽  
Emission Computed Tomography ◽  
Myocardial Perfusion Defect ◽  
Cross Sectional ◽  
History Of

Background: The frontal QRS-T angle is the angle between ventricular depolarization and repolarization. The QRS-T angle abnormalities will mirror the electrical instability, placing the patient in high risk of cardiac arrhythmia and sudden cardiac death. This study was conducted to analyzed as if the QRS-T angle will predict the myocardial perfusion defect in acute ST elevation myocardial infarction (STEMI).   Methods: This is a cross sectional study which conducted in patients with previous history of STEMI in H. Adam Malik General Hospital Medan from June 2018 until March 2020. The patients will then be undergoing electrocardiography (ECG) and myocardial perfusion scintigraphy (SPECT) to acquire the frontal QRS-T angle and myocardial perfusion defect score.   Results: Over 40 patients with prior STEMI we found the frontal QRS-T angle has a positive moderate correlation (r = 0,543; p < 0,001) with myocardial perfusion defect. The best cut-off value for frontal QRS-T angle to predict myocardial perfusion defect is > 70o with sensitivity and specificity of 70.6% and 82.6%, respectively.   Conclusions: The frontal QRS-T angle is an independent predictor for myocardial perfusion defect in patient with previous history of STEMI.   Keywords:  STEMI; frontal QRS-T angle; myocardial perfusion defect.

scholarly journals A case report: adenosine triggered myocardial infarction during myocardial perfusion stress test imaging in a diabetic patient

2021 ◽  
Vol 5 (4) ◽  
Author(s):  
Maarten de Mulder ◽  
Menno van Gameren ◽  
Eric A van Asperen ◽  
Martijn Meuwissen
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Perfusion ◽  
Single Photon ◽  
Thrombus Formation ◽  
Stress Test ◽  
Photon Emission ◽  
Coronary Perfusion Pressure ◽  
Emission Computed Tomography ◽  
Coronary Perfusion ◽  
Starting Point

Abstract Background Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) can in general be used safely in daily clinical practice. However, under the right circumstances, it can lead to serious complications. Case summary A 68-year-old female patient with diabetes and a history of inferior ST-elevation myocardial infarction 8 years earlier, visited our outpatient clinic with atypical chest discomfort. In order to assess whether this is due to myocardial ischaemia, MPI-SPECT was ordered. As it was suspected she would not achieve sufficient exercise levels, pharmacologic stress using adenosine was arranged. During the scan, she developed acute myocardial infarction. Subsequent urgent coronary angiography demonstrated a subtotal stenosis in the proximal left anterior descending coronary artery which was successfully stented. She was still free from angina 4 months later. Discussion The combination of a reduced systemic and coronary perfusion pressure in the presence of an exhausted coronary autoregulation, may be a starting point for local geometrical changes that initiate the classic cascade of thrombus formation and acute occlusion of coronary arteries during MPI-SPECT. This illustrates the need for continuous patient and electrocardiogram monitoring.

scholarly journals NOGA-Guided Analysis of Regional Myocardial Perfusion Abnormalities Treated With Intramyocardial Injections of Plasmid Encoding Vascular Endothelial Growth Factor A-165 in Patients With Chronic Myocardial Ischemia

Circulation ◽  
2005 ◽  
Vol 112 (9_supplement) ◽  
Author(s):  
Mariann Gyöngyösi ◽  
Aliasghar Khorsand ◽  
Sholeh Zamini ◽  
Wolfgang Sperker ◽  
Christoph Strehblow ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Perfusion Defect ◽  
Single Photon ◽  
Photon Emission ◽  
Tracer Uptake ◽  
Emission Computed Tomography ◽  
Single Photon Emission ◽  
Single Photon Emission Computed ◽  
Photon Emission Computed Tomography

Background— The aim of this substudy of the EUROINJECT-ONE double-blind randomized trial was to analyze changes in myocardial perfusion in NOGA-defined regions with intramyocardial injections of plasmid encoding plasmid human (ph)VEGF-A 165 using an elaborated transformation algorithm. Methods and Results— After randomization, 80 no-option patients received either active, phVEGF-A 165 (n=40), or placebo plasmid (n=40) percutaneously via NOGA-Myostar injections. The injected area (region of interest, ROI) was delineated as a best polygon by connecting of the injection points marked on NOGA polar maps. The ROI was projected onto the baseline and follow-up rest and stress polar maps of the 99m-Tc-sestamibi/tetrofosmin single-photon emission computed tomography scintigraphy calculating the extent and severity (expressed as the mean normalized tracer uptake) of the ROI automatically. The extents of the ROI were similar in the VEGF and placebo groups (19.4±4.2% versus 21.5±5.4% of entire myocardium). No differences were found between VEGF and placebo groups at baseline with regard to the perfusion defect severity (rest: 69±11.7% versus 68.7±13.3%; stress: 63±13.3% versus 62.6±13.6%; and reversibility: 6.0±7.7% versus 6.7±9.0%). At follow-up, a trend toward improvement in perfusion defect severity at stress was observed in VEGF group as compared with placebo (68.5±11.9% versus 62.5±13.5%, P =0.072) without reaching normal values. The reversibility of the ROI decreased significantly at follow-up in VEGF group as compared with the placebo group (1.2±9.0% versus 7.1±9.0%, P =0.016). Twenty-one patients in VEGF and 8 patients in placebo group ( P <0.01) exhibited an improvement in tracer uptake during stress, defined as a ≥5% increase in the normalized tracer uptake of the ROI. Conclusions— Projection of the NOGA-guided injection area onto the single-photon emission computed tomography polar maps permits quantitative evaluation of myocardial perfusion in regions treated with angiogenic substances. Injections of phVEGF A 165 plasmid improve, but do not normalize, the stress-induced perfusion abnormalities.

scholarly journals Increased accuracy of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy using iterative reconstruction of images

2016 ◽  
Vol 73 (5) ◽  
pp. 469-471
Author(s):  
Milos Stevic ◽  
Marina Vlajkovic
Keyword(s):  
Coronary Artery ◽  
Myocardial Perfusion ◽  
Iterative Reconstruction ◽  
False Positive ◽  
Perfusion Defect ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Positive Finding ◽  
Bivariate Correlation

Background/Aim. Filtered back projection (FBP) is a common way of processing myocardial perfusion imaging (MPI) studies. There are artifacts in FBP which can cause falsepositive results. Iterative reconstruction (IR) is developed to reduce false positive findings in MPI studies. The aim of this study was to evaluate the difference in the number of false positive findings in MPI studies, between FBP and IR processing. Methods. We examined 107 patients with angina pectoris with MPI and coronary angiography (CAG), 77 man and 30 woman, aged 32?82. MPI studies were processed with FBP and with IR. Positive finding at MPI was visualization of the perfusion defect. Positive finding at CAG was stenosis of coronary artery. Perfusion defect at MPI without coronary artery stenosis at CAG was considered like false positive. The results were statistically analyzed with bivariate correlation, and with one sample t-test. Results. There were 20.6% normal, and 79.4% pathologic findings at FBP, 30.8% normal and 69.2% pathologic with IR and 37.4% normal and 62.6% pathologic at CAG. FBP produced 19 false-positive findings, at IR 11 false positive findings. The correlation between FBP and CAG was 0.658 (p < 0.01) and between IR and CAG 0.784 (p < 0.01). The number of false positive findings at MPI with IR was significantly lower than at FBP (p < 0.01). Conclusion. Our study shows that IR processing MPI scintigraphy has less number of false positive findings, therefore it is our choice for processing MPI studies.

scholarly journals Coronary collaterals provide more than half of normal perfusion in patients with coronary artery disease - quantification by myocardial perfusion SPECT during elective balloon occlusion

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
B Harris ◽  
S Warren ◽  
E Persson ◽  
R Bhindi ◽  
M Ringborn ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Collateral Circulation ◽  
Perfusion Defect ◽  
Coronary Occlusion ◽  
Single Photon ◽  
Photon Emission ◽  
Balloon Occlusion ◽  
Spect Imaging ◽  
Emission Computed Tomography ◽  
Occlusion Time

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND The coronary collateral circulation is a preformed network of anastomotic connections acting as a "natural bypass" mechanism. Whilst the prevalence of collaterals varies between species, approximately 25% of patients have angiographically visible robust collaterals at the time of ST elevation myocardial infarction. While the presence of collaterals is associated with improved outcomes, the magnitude of myocardial perfusion which can be provided by the collateral circulation remains uncertain. PURPOSE The aim was to quantify collateral myocardial perfusion during experimental coronary balloon occlusion in patients with CAD. METHODS The study was approved by the local investigational review board, and all patients provided informed consent. Patients without prior infarction, bypass surgery, or angiographically visible collaterals undergoing elective percutaneous transluminal coronary angioplasty (PTCA) to a single epicardial vessel, underwent two scans with 99mTc-sestamibi myocardial perfusion single-photon emission computed tomography (SPECT). All subjects underwent at least three minutes of angiographically verified complete balloon occlusion, at which time an intravenous injection of the radiotracer was administered, followed by SPECT imaging. A second radiotracer injection followed by SPECT imaging was performed 24 hours after PTCA. RESULTS The study included 21 patients (median [interquartile range] age 70 [56-74] years, 52% male). The degree of diameter stenosis of treated vessels ranged from 60-99%, with successful PTCA performed with a mean 5-minute balloon occlusion time, resulting in ≤20% residual stenosis in all cases. The vessels undergoing PTCA were 6 in the LAD, 5 in the LCx, and 10 in the RCA. For the cohort, the size of the perfusion defect was 16 [8-30]% of the LV and the collateral perfusion at rest within the perfusion defect was 64 [58-68]% of normal perfusion within that region. Collateral perfusion was negatively correlated with perfusion defect size (R2 = 0.85, p &lt; 0.001), but did not differ by sex (p = 0.27) or age (p = 0.58). CONCLUSIONS: This is the first study to describe the magnitude of microvascular collateral perfusion in CAD. On average, despite coronary occlusion and an absence of angiographically visible collateral vessels, collaterals provide approximately 60% of the perfusion that reaches the jeopardized myocardium during coronary occlusion. This magnitude of collateral perfusion is much higher than previously speculated. A previous study using microspheres in dogs found that collateral perfusion in the setting of an occluded vessel was 6% of normal. By comparison, the current study found ten times greater collateral perfusion in patients with CAD. Abstract Figure. Collateral perfusion during occlusion.

Abstract 15252: Segmental Myocardial Perfusion Improves after Repeated Intramyocardial Cell Injection

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Imke Mann ◽  
Sander F Rodrigo ◽  
Jan van Ramshorst ◽  
Saskia L Beeres ◽  
Jaap J Zwaginga ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Bone Marrow Mononuclear Cell ◽  
Repeated Injection ◽  
Refractory Angina ◽  
Rest Perfusion ◽  
Refractory Angina Pectoris ◽  
First Time

Introduction: We previously demonstrated that intramyocardial bone marrow mononuclear cell (MNC) injection improves segmental myocardial perfusion. This study was designed to evaluate in patients with recurrent refractory angina the effect of repeated injection on segmental myocardial perfusion. Methods: Twenty-one patients with recurrent refractory angina pectoris, who received 100x10^6 autologous MNC intramyocardially using the NOGA-system for a second time, were enrolled. Single-photon emission computed tomography was performed at baseline and 3 months after both injection procedures. The myocardium was divided into 17 segments and in both stress and rest images, segmental tracer activity was categorized on a 4-point scale. (1=>75%; 2=50%-74%; 3=25%-49%; 4=<25%) Segments demonstrating increased perfusion of at least 1 point in stress or rest perfusion were categorized as improved. Results: The second injection procedure was 4.6 ± 2.5 years after the first. In total, 139 segments were injected for the first time during either of the procedures, of which 80(58%) segments improved. Repeated injection in the same segment was performed in 45 segments. Of these segments, 18(40%) improved, less than after a first injection (P=0.030). Repeatedly injected segments can be subdivided in 29 previously responding segments (improved after the first injection) and 16 previously non-responding segments (not improved after the first injection). Of the responding segments, 13(45%) segments improved after repeated injection and of the non-responding segments, 5(31%) segments improved. This difference was not significant (P=.476). Conclusions: Segmental myocardial perfusion can improve after repeated intramyocardial MNC injection independently of the effect of the first injection, but the first injection is more effective.

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