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  • 1.
    Bothe, Wolfgang
    et al.
    Stanford University School of Medicine, USA.
    Ennis, Daniel
    Stanford University School of Medicine, USA.
    Carlhäll, Carl Johan
    Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Stanford University School of Medicine, USA.
    Nguyen, Tom
    Stanford University School of Medicine, USA.
    Timek, Tomasz
    Stanford University School of Medicine, USA.
    Lai, David
    Stanford University School of Medicine, USA.
    Itoh, Akinobu
    Stanford University School of Medicine, USA.
    Ingels, Neil
    Stanford University School of Medicine & Research Institute of the Palo Alto Medical Foundation, California, USA.
    Miller, Craig
    Stanford University School of Medicine, USA.
    Regional Mitral Leaflet Opening During Acute Ischemic Mitral Regurgitation2009In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 18, no 6, p. 586-597Article in journal (Refereed)
    Abstract [en]

    Background and aim of the study

    Diastolic mitral valve (MV) opening characteristics during ischemic mitral regurgitation (IMR) are poorly characterized. The diastolic MV opening dynamics was quantified along the entire valvular coaptation line in an ovine model of acute IMR.

    Methods

    Ten radiopaque markers were sutured in pairs on the anterior (A1-E1) and corresponding posterior (A2-E2) leaflet edges from the anterior (A1/A2) to the posterior (E1/E2) commissure in 11 adult sheep. Immediately after surgery, 4-D marker coordinates were obtained before and during occlusion of the proximal left circumflex coronary artery. Distances between marker pairs were calculated throughout the cardiac cycle every 16.7 ms. Leaflet opening was defined as the time after end-systole (ES) when the first derivative of the distance between marker pairs was greater than a threshold value of 3 cm/s. Valve opening velocity was defined as the maximum slope of marker pair tracings.

    Results

    Hemodynamics were consistent with acute ischemia, as reflected by increased MR grade (0.5 ± 0.3 versus 2.3 ± 0.7, p <0.05), decreased contractility (dP/dtmax: 1,948 ± 598 versus 1,119 ± 293 mmHg/s, p <0.05), and slower left ventricular relaxation rate (dP/dtmin: −1,079 ± 188 versus −538 ± 147 mmHg/s, p <0.05). During ischemia, valve opening occurred earlier (A1/A2: 112 ± 28 versus 83 ± 43 ms, B1/B2: 105 ± 32 versus 68 ± 35 ms, C1/C2: 126 ± 25 versus 74 ± 37 ms, D1/D2: 114 ± 28 versus 71 ± 34 ms, E1/E2: 125 ± 29 versus 105 ± 33 ms; all p <0.05) and was slower (A1/A2: 16.8 ± 9.6 versus 14.2 ± 9.4 cm/s, B1/B2: 40.4 ± 9.9 versus 32.2 ± 10.0 cm/s, C1/C2: 59.0 ± 14.9 versus 50.4 ± 18.1 cm/s, D1/D2: 34.4 ± 10.4 versus 25.5 ± 10.9 cm/s; all p <0.05), except at the posterior edge (E1/E2: 13.3 ± 8.7 versus 10.6 ± 7.2 cm/s). The sequence of regional mitral leaflet separation along the line of coaptation did not change with ischemia.

    Conclusion

    Acute posterolateral left ventricular ischemia causes earlier leaflet opening, probably due to a MR-related elevation in left-atrial pressure; reduces leaflet opening velocity, potentially reflecting an impaired left ventricular relaxation rate; and does not perturb the homogeneous temporal pattern of regional valve opening along the line of coaptation. Future studies will confirm whether these findings are apparent in patients with chronic IMR, and may help to refine the current strategies used to treat IMR.

  • 2.
    Fyrenius, Anna
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Janerot Sjöberg, Birgitta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Major and minor axes of the normal mitral annulus2001In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 10, no 2, p. 146-152Article in journal (Refereed)
    Abstract [en]

    Background and aim of the study: A dilated or abnormally shaped mitral annulus is a common cause of mitral valve regurgitation, and may be cured by annuloplastic surgery. Multiplane transesophageal echocardiography (TEE) is the diagnostic technique of choice. Our aim was to evaluate and suggest two-dimensional TEE reference values from a standardized procedure of measuring the mitral annular major and minor axes, and their cyclic changes. Methods: The annulus was approximated elliptic in the horizontal plane. The intercommissural (IC, major axis) and anteroposterior (AP, minor axis) distances were measured at end-systole (ES), at maximal valve opening (MO), and at end-diastole (ED) from a mid-esophageal view, in 13 men and eight women with normal echocardiographic findings. Indexed values and reproducibility were calculated. Results: The success rate was 100% at ES, 90% at MO, and 29% at ED. ES distances were largest (p <0.001) and most reproducible (5-5.9%). Body weight, but not height or age, had a significant impact. ES 95% prediction intervals for IC were 27 to 46 mm (16-23 mm/m2) and 22 to 36 mm (13-18 mm/m2) for AP (p <0.001). Corresponding body weight-corrected intervals were 0.39 to 0.59 (IC) and 0.32 to 0.48 (AP) mm/kg. No subject had IC:AP <1.1 together with an AP >0.45 mm/kg. Conclusion: Among measurements made at ES, MO and ED, those at ES provided the most reproducible results, and high-quality images were obtained in normal, non-obese subjects. The distances should be judged in relation to body weight or surface area and each other. The largest IC distance and the most elliptic shape were at ES, while the annulus was minimal at ED. The procedure and normal ranges presented may contribute to the evaluation of patients with mitral regurgitation.

  • 3.
    Hultkvist, Henrik
    et al.
    Linköping University, Department of Medical and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Vánky, Farkas
    Linköping University, Department of Medical and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Svedjeholm, Rolf
    Linköping University, Department of Medical and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    The combined impact of postoperative heart failure and euroScore on long-term outcome after surgery for aortic stenosis2011In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 20, no 6, p. 633-638Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND AIM OF THE STUDY:

    Although the EuroSCORE was developed for predicting operative mortality after cardiac surgery, it has also been shown to predict long-term mortality. It has been reported that postoperative heart failure (PHF) in association with surgery, albeit comparatively benign in the short term, has a profound impact on five-year survival after surgery for aortic stenosis (AS). The study aim was to determine the combined impact of EuroSCORE and PHF on long-term survival after isolated aortic valve replacement (AVR) for AS.

    METHODS:

    A total of 397 patients (48% females; average age 70 +/- 10 years) who underwent AVR for AS at the authors' institution between 1995 and 2000 was studied. The cohort was subdivided according to the additive EuroSCORE into a high-risk group (EuroSCORE >7) and a low-risk group (EuroSCORE < or = 7), and further analyzed in relation to PHF.

    RESULTS:

    The average follow up was 8.1 years (range: 5.2-11.2 years). Forty-five patients (11%) were treated for procedure-associated PHF. Patients with or without PHF and a high-risk EuroSCORE had crude five-year survivals of 57% and 64%, respectively (p = 0.6), whereas those with or without PHF but with a low-risk EuroSCORE had crude five-year survivals of 58% and 89%, respectively (p = 0.0003).

    CONCLUSION:

    Both PHF and a high EuroSCORE were associated with poor long-term survival. The role of PHF per se for the long-term prognosis was illustrated by the fact that the negative impact on long-term survival was almost as profound in patients of the low-risk group as of the high-risk group.

  • 4.
    Nguyen, Tom
    et al.
    Stanford University.
    Itoh, Akinobu
    Stanford University.
    Carlhäll, Carljohan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Stanford University School of Medicine.
    Oakes, Robert
    Stanford University.
    Liang, David
    Stanford University.
    Ingels, Neil B.
    Stanford University.
    Miller, D. Craig
    Stanford University.
    Functional uncoupling of the mitral annulus and left ventricle with mitral regurgitation and dopamine2008In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 17, p. 168-178Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The mitral annulus and left ventricle are generally thought to be functionally coupled, in the sense that increases in left ventricular (LV) size, as seen in ischemic mitral regurgitation (MR), or decreases in LV size, as seen with inotropic stimulation, are thought to increase or decrease annular dimensions in similar manner. The study aim was to elucidate the functional relationship between the mitral annulus and left ventricle during acute MR and inotrope-induced MR reduction.

    METHODS: Radiopaque markers were implanted on the left ventricle and mitral annulus of five adult sheep. A suture was placed on the central scallop of the posterior mitral leaflet and exteriorized through the atrial-ventricular groove. Open-chest animals were studied at baseline (CTRL), at seconds after pulling on the suture to create moderate-severe 'pure' MR (PULL), and after titration of dopamine until the MR grade was maximally reduced (PULL+DOPA). This process was repeated two to three times for each animal.

    RESULTS: The MR grade was increased with PULL (from 0.5 +/- 0.01 to 3.4 +/- 0.4, p < 0.01) and decreased after PULL+DOPA (from 3.4 +/- 0.4 to 1.5 +/- 0.9, p < 0.001). PULL resulted in an increase in mitral annular (MA) area, predominantly by an increase in the muscular mitral annulus. PULL+DOPA caused a decrease in MA area, but the LV volume and dimensions were not altered with either PULL or PULL+DOPA.

    CONCLUSION: The acute geometric response to 'pure' MR and inotrope-induced MR reduction was limited to the mitral annulus. Surprisingly, the LV volume and dimensions did not change with acute MR or with inotrope-induced MR reduction. This suggests that, under these two conditions in an ovine model, the mitral annulus and left ventricle are functionally uncoupled.

  • 5.
    Peterffy, Arpad
    et al.
    Östergötlands Läns Landsting, Heart Centre.
    Szabó, Zoltán
    Linköping University, Department of Medicine and Care. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre.
    Can mechanical valve prostheses be recommended in the tricuspid position?1996In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 5, no 5, p. 570-571Article in journal (Refereed)
  • 6. Tibayan, Frederick A.
    et al.
    Rodriguez, Filiberto
    Langer, Frank
    Zasio, Mary K.
    Bailey, Lynn
    Liang, David
    Daughters, George T
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation.
    Ingels, Neil B.
    Miller, Craig
    Increases in mitral leaflet radii of curvature with chronic ischemic mitral regurgitation2004In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 13, no 5, p. 772-778Article in journal (Refereed)
1 - 6 of 6
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