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- Kvitting, J.P., et al.
(författare)
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Analysis of human myocardial dynamics using virtual markers based on magnetic resonance imaging
- 2010
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 30:1, s. 23-29
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Tidskriftsartikel (refereegranskat)abstract
- Background: Myocardial dynamics are three-dimensional (3D) and time-varying. Cineradiography of surgically implanted makers in animals or patients is accurate for assessing these events, but this invasive method potentially alters myocardial motion. The aim of the study was to quantify myocardial motion using magnetic resonance imaging (MRI) and hence to provide a non-invasive approach to characterize 3D myocardial dynamics. Methods: Myocardial motion was quantified in ten normal volunteers by tracking the Lagrangian motion of individual points (i.e. virtual markers), based on time-resolved 3D phase-contrast MRI data and Fourier tracking. Nine points in the myocardium were tracked over the entire cardiac cycle, allowing a wire frame model to be generated and systolic and diastolic events identified. Results: Radius of curvature of the left ventricular (LV) wall was calculated from the virtual markers; the ratio between the anterior–posterior (AP) and septal–lateral (SL) walls in the LV shows an oval shape of the apical short axis plane at end systole (ES) and more circular at end diastole (ED). The AP/SL ratio for the basal plane shows an oval shape at ES and ED. We found that the rotation of the basal plane in ES was less compared to the apical plane [−2·0 ± 2·2 versus 4·1 ± 2·6 degrees (P<0·005)]. The apical plane rotated counter clock wise as viewed from the apex. Conclusion: This new non-invasive tool, despite current limitations in temporal and spatial resolution, may provide a comprehensive set of virtual myocardial markers throughout the entire LV without the confounding effects introduced by surgical implantation.
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- Svensson, Anders S., et al.
(författare)
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Changes in serum cystatin C, creatinine, and C-reactive protein after cardiopulmonary bypass in patients with normal preoperative kidney function.
- 2016
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Ingår i: Nephrology (Carlton. Print). - : Wiley-Blackwell. - 1320-5358 .- 1440-1797. ; 21:6, s. 519-525
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The use of cardiopulmonary bypass (CPB) can cause changes in serum creatinine and cystatin C independent of glomerular filtration rate. We aimed to quantify the temporal changes of these biomarkers and C-reactive protein (CRP) after CPB.METHODS: This was a prospective study at an academic medical center between April and October 2013. We compared postoperative changes in serum creatinine and cystatin C in 38 patients with normal preoperative kidney function who underwent cardiac surgery using CPB and did not develop perioperative acute kidney injury (AKI). The effect of inflammation on intra-individual changes was examined in mixed effects regressions, using measurements of pre- and postoperative CRP.RESULTS: Both serum creatinine (79.9 ± 22.7 vs. 92.6 ± 21.4 µmol/L, p = 0.001) and cystatin C (1.16 ± 0.39 vs. 1.33 ± 0.37 mg/L, p = 0.012) decreased significantly in the first 8 hours postoperatively compared to preoperatively, as a result of hemodilution. Thereafter serum creatinine returned to preoperative levels, whereas serum cystatin C continued to rise and was significantly elevated at 72 hours post-CPB compared to preoperative levels (1.53 ± 0.48 vs. 1.33 ± 0.37 mg/L, p = 0.003). CRP levels increased significantly post-CPB and were significantly associated with increases in both serum creatinine and cystatin C.CONCLUSIONS: Serum creatinine and cystatin C appear not to be interchangeable biomarkers during and immediately after CPB. Processes unrelated to kidney function such as acute inflammation have a significant effect on post-CPB changes in these biomarkers, and may result in significant increases in serum cystatin C that could erroneously be interpreted as AKI. This article is protected by copyright. All rights reserved.
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- Svensson, Anders S., et al.
(författare)
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Comparison of serum cystatin C and creatinine changes after cardiopulmonary bypass in patients with normal preoperative kidney function
- 2013
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Ingår i: International Urology and Nephrology. - : Springer Netherlands. - 0301-1623 .- 1573-2584. ; 45:6, s. 1597-1603
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Tidskriftsartikel (refereegranskat)abstract
- PurposeSerum creatinine is used ubiquitously to estimate glomerular filtration rate and to diagnose acute kidney injury after cardiac surgery. Serum cystatin C is a novel biomarker that has emerged as a possible diagnostic alternative to serum creatinine. It is unclear if the dynamic changes in serum cystatin C immediately following cardiopulmonary bypass (CPB) differ from those of serum creatinine in patients with normal preoperative kidney function.MethodsWe compared changes in serum levels of creatinine and cystatin C by measuring them serially in 19 patients undergoing CPB. Within-patient differences for serum creatinine and serum cystatin C were compared by repeated measures ANOVA.ResultsSerum creatinine and cystatin C levels showed significant correlation with each other. Both biomarkers showed a significant decrease after CPB, but their serum concentrations reverted to pre-CPB levels within 12 h. Serum levels of serum creatinine remained unchanged from baseline levels throughout 72-h post-CPB. In contrast, serum cystatin C levels rose further and became significantly higher compared to baseline within 48 h. Serum cystatin C remained significantly elevated at 48- and 72-h post-CPB.ConclusionsProcesses that determine the serum concentrations of serum creatinine and cystatin C in the post-CPB period affect the two biomarkers differently, suggesting that the two are not interchangeable as diagnostic markers of glomerular filtration rate. Future studies are needed to examine if these discrepancies are related to differences in their production rates, in their ability to detect small changes in glomerular filtration rate, or to a combination of these, and to determine the effect of such differences on the diagnostic and prognostic accuracy of the two biomarkers.
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