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  • 1.
    Lindenberger, Marcus
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Fedorowski, Arthur
    Lund Univ, Sweden; Sickle Univ Hosp, Sweden.
    Melander, Olle
    Lund Univ, Sweden.
    Gallo, Widet
    Lund Univ, Sweden.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Skoog, Johan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Cardiovascular biomarkers and echocardiographic findings at rest and during graded hypovolemic stress in women with recurrent vasovagal syncope2019In: Cardiovascular Electrophysiology, ISSN 1045-3873, E-ISSN 1540-8167, Vol. 30, no 12, p. 2936-2943Article in journal (Refereed)
    Abstract [en]

    Introduction Vasovagal reflex is the most common type of syncope but its etiology is not fully elucidated. Venous return and cardiac output are key in hemodynamic control. The aim of the study was to assess cardiovascular biomarkers and echocardiographic measures at rest and during hypovolemia in women with and without a history of vasovagal syncope. Methods Fourteen women (aged 18-30) suffering from recurrent vasovagal syncope and 15 age-matched healthy women were included. Graded lower body negative pressure (LBNP) was used to create central hypovolemic stress until signs of presyncope occurred. Echocardiography was applied at rest and throughout LBNP. Cardiovascular biomarkers: copeptin, mid-regional proadrenomedullin, mid-regional pro-ANP, C-terminal proendothelin-1, and plasma norepinephrine were measured both at rest and throughout graded hypovolemia to presyncope. Results Women prone to vasovagal syncope presented with a narrower right ventricle (RV) (29 +/- 1 vs 32 +/- 1 mm, P amp;lt; .05), smaller left atrium (36 +/- 2 vs 47 +/- 3 cm(3), P amp;lt; .01) and lower cardiac output at rest (3.1 +/- 0.2 vs 3.7 +/- 0.2 L/min, P amp;lt; .05) and during graded hypovolemia (P amp;lt; .05). Copeptin was elevated at rest (4.3 +/- 0.8 vs 2.5 +/- 0.2 pmol/L, P amp;lt; .05) and increased more in women with vasovagal syncope during progression of LBNP (P amp;lt; .01). At rest, lower C-terminal proendothelin-1 (35 +/- 5 vs 46 +/- 2 pmol/L, P amp;lt; .05) and higher norepinephrine levels (1.1 +/- 0.1 vs 0.8 +/- 0.1 nmol/L, P amp;lt; .01) were seen in women with vasovagal syncope. Conclusion Women prone to vasovagal syncope demonstrate reduced cardiac preload, lower cardiac output, as well as increased release of vasopressin in rest and during hypovolemic challenge. The results emphasize the importance of venous return and cardiac output in the pathogenesis of vasovagal syncope.

  • 2.
    Nelzén, Oskar
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Skoog, Johan
    Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine.
    Länne, Toste
    Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery. Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Zachrisson, Helene
    Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine.
    Prediction of Post-interventional Outcome in Great Saphenous Vein Incompetence: The Role of Venous Plethysmography with Selective Superficial Vein Occlusion2016In: European Journal of Vascular and Endovascular Surgery, ISSN 1078-5884, E-ISSN 1532-2165, Vol. 52, no 3, p. 377-384Article in journal (Refereed)
    Abstract [en]

    Objective/Background

    To evaluate whether the outcome of radiofrequency ablation (RFA) treatment of great saphenous vein (GSV) incompetence may be predicted using strain-gauge plethysmography (SGP) with selective occlusion of the superficial venous system.

    Methods

    Seventeen patients (20 limbs) underwent endovenous RFA treatment for GSV incompetence (Clinical Etiology Anatomy Pathophysiology classification C2–C5; “C-group”). Duplex ultrasound (DUS) and SGP were performed with selective occlusion of superficial veins before and after RFA. Selective superficial occlusion was validated, in a control group (C-group) of 12 patients (14 legs), by ascending phlebography. In the RFA group, the time taken to reach 50% and 90% (T50, T90) of maximum venous volume was measured, as well as relative maximal reflux rates (%EV/min). The methodological error and coefficient of variation (CV) were assessed.

    Results

    Nineteen of 20 legs had complete post-operative GSV obliteration using DUS, and refilling times were improved after RFA (T50 11 ± 3 vs. 19 ± 3 s; p < .001; T90 27 ± 5 vs. 47 ± 6 s; p < .001). With SGP, the methodological error and CV for T50 were 4 s and 16%, respectively. Equivalence between pre-operative superficial occlusion and post-operative baseline measurements was achieved in 15 of 17 legs for T50, and 12 of 17 for T90 (three of the 20 legs were excluded due to treatment failure [n = 1], and untreated perforating veins [n = 2]). Mean differences (95% confidence interval) were within the equivalence ranges (T50 1 [–1 to 3] seconds; T90 –3 [–11 to 4] seconds). In the C-group superficial vein occlusion was possible in 12 of 14 legs. The remaining patient (two legs) showed incomplete superficial vein occlusion at ankle level (lipodermatosclerosis) and complete superficial vein occlusion at calf level.

    Conclusion

    SGP with standardized superficial venous occlusion seems to be a reliable method for identifying venous reflux and may be useful in predicting the results of successful RFA treatment.

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  • 3.
    Nelzén, Oskar
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Skoog, Johan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery. Linköping University, Faculty of Medicine and Health Sciences.
    Zachrisson, Helene
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Residual reflux despite technical successful treatment of Great Saphenous Vein Incompetence?2018In: Charing Cross Venous Workshop strain gauge plethysmography 2018, 2018Conference paper (Other academic)
  • 4.
    Nelzén, Oskar
    et al.
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Skoog, Johan
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Öster, Malin
    Linköping University, Department of Health, Medicine and Caring Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Zachrisson, Helene
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Impact on venous haemodynamics after treatment of great saphenous vein incompetence using plethysmography and duplex ultrasound2020In: Phlebology, ISSN 0268-3555, E-ISSN 1758-1125, article id 0268355519898952Article in journal (Refereed)
    Abstract [en]

    Objectives

    To evaluate postoperative venous haemodynamics and quality of life after treatment of great saphenous vein (GSV) incompetence.

    Methods

    Radiofrequency ablation and high ligation and stripping were performed in 62 patients (65 limbs) and 58 (65 limbs), respectively. Phlebectomies were performed in both modalities. Strain-gauge plethysmography on the foot combined with superficial venous occlusion was used to measure refilling time after knee bends. Strain-gauge plethysmography, duplex ultrasound and quality of life were assessed before and one month after treatment.

    Results

    Duplex ultrasound displayed successful intervention in all but two limbs. Refilling time increased similar in radiofrequency ablation and high ligation and stripping after treatment (p < 0.001). Postoperatively, strain-gauge plethysmography detected remaining reflux in 71% of the patients. Multivariate analysis showed that two or more incompetent calf branches were associated with remaining reflux (OR 4.82 (95% CI: 1.33–17.5), p = 0.02). No difference in quality of life was seen in patients with remaining reflux.

    Conclusions

    Despite successful treatment, a majority of the limbs showed remaining reflux, in which incompetent calf branches appear to play an important role.

    Clinicaltials.gov: Lower Limb Venous Insufficiency and the Effect of Radiofrequency Treatment Versus Open Surgery. Nr: NCT02397226

  • 5. Order onlineBuy this publication >>
    Skoog, Johan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Cardiovascular regulation in women with vasovagal syncope: With special reference to the venous system2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Although vasovagal syncope (VVS) is a common clinical condition the mechanisms behind VVS remain elusive. Upright posture is the major trigger of VVS and lower limb blood pooling affecting cardiac output has been proposed as a major determinant. The overall aim of this thesis was twofold. First, to develop new methodology for calculating limb venous compliance. Second, to study lower limb venous volume load and cardiovascular responses during hypovolemic circulatory stress caused by lower body negative pressure (LBNP) in healthy women and women with VVS, emphasizing compensatory mechanisms to maintain central blood volume.

    Net fluid filtration was associated with an underestimation ofvenous compliance. This could be accounted for with a correctionmodel. Further, a new venous wall model made it possible to adopt thevenous pressure-volume curve through the entire pressure range andthus provide a valid characterization of venous compliance.

    Calf blood pooling was similar between the groups and was not associated with tolerance to hypovolemic circulatory stress. Venous compliance was reduced at low venous pressures in VVS and correlated with decreased tolerance to circulatory stress. VVS women displayed attenuated sympathetic vasoconstrictor responses during graded circulatory stress, and mobilization of arm capacitance blood as well as capillary fluid absorption from extra- to intravascular space were reduced. Accordingly, more pronounced reductions in cardiac output were found in VVS. Thus, reduced compensatory mechanisms to maintain cardiac output could contribute to the pathogenesis oforthostatic VVS.

    In healthy women, rapid pooling in the lower limb was associated with higher tolerance to circulatory stress and more efficient cardiovascular responses, in part due to speed-dependent baroreflex-mediated sympathetic activation. In VVS however, rapid lower limb blood pooling was associated with lower tolerance and deficient cardiovascular responses. No speed-dependent baroreflexmediated sympathetic activation was found in VVS, indicating welldefined differences in cardiovascular regulation already in the initial responses to orthostatic stress.

    List of papers
    1. Calf venous compliance measured by venous occlusion plethysmography: methodological aspects.
    Open this publication in new window or tab >>Calf venous compliance measured by venous occlusion plethysmography: methodological aspects.
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    2015 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 115, no 2, p. 245-56Article in journal (Refereed) Published
    Abstract [en]

    PURPOSE: Calf venous compliance (C calf) is commonly evaluated with venous occlusion plethysmography (VOP) during a standard cuff deflation protocol. However, the technique relies on two not previously validated assumptions concerning thigh cuff pressure (P cuff) transmission and the impact of net fluid filtration (F filt) on C calf. The aim was to validate VOP in the lower limb and to develop a model to correct for F filt during VOP.

    METHODS: Strain-gauge technique was used to study calf volume changes in 15 women and 10 age-matched men. A thigh cuff was inflated to 60 mmHg for 4 and 8 min with a subsequent decrease of 1 mmHg s(-1). Intravenous pressure (P iv) was measured simultaneously. C calf was determined with the commonly used equation [Compliance = β 1 + 2β 2 × P cuff] describing the pressure-compliance relationship. A model was developed to identify and correct for F filt.

    RESULTS: Transmission of P cuff to P iv was 100 %. The decrease in P cuff correlated well with P iv reduction (r = 0.99, P < 0.001). Overall, our model showed that C calf was underestimated when F filt was not accounted for (all P < 0.01). F filt was higher in women (P < 0.01) and showed a more pronounced effect on C calf compared to men (P < 0.05). The impact of F filt was similar during 4- and 8-min VOP.

    CONCLUSIONS: P cuff is an adequate substitute for P iv in the lower limb. F filt is associated with an underestimation of C calf and differences in the effect of F filt during VOP can be accounted for with the correction model. Thus, our model seems to be a valuable tool in future studies of venous wall function.

    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-113393 (URN)10.1007/s00421-014-3009-4 (DOI)000347725800003 ()25272971 (PubMedID)
    Available from: 2015-01-17 Created: 2015-01-17 Last updated: 2017-12-05
    2. Reduced venous compliance: an important determinant for orthostatic intolerance in women with vasovagal syncope
    Open this publication in new window or tab >>Reduced venous compliance: an important determinant for orthostatic intolerance in women with vasovagal syncope
    Show others...
    2016 (English)In: American Journal of Physiology. Regulatory Integrative and Comparative Physiology, ISSN 0363-6119, E-ISSN 1522-1490, Vol. 310, no 3, p. R253-R261Article in journal (Refereed) Published
    Abstract [en]

    The influence of lower limb venous compliance on orthostatic vasovagal syncope (VVS) is uncertain. The most widespread technique to calculate venous compliance uses a nonphysiological quadratic regression equation. Our aim was therefore to construct a physiologically derived venous wall model (VWM) for calculation of calf venous compliance and to determine the effect of venous compliance on tolerance to maximal lower body negative pressure (LBNP). Venous occlusion plethysmography was used to study calf volume changes in 15 women with VVS (25.5 +/- 1.3 yr of age) and 15 controls (22.8 +/- 0.8 yr of age). The fit of the VWM and the regression equation to the experimentally induced pressure-volume curve was examined. Venous compliance was calculated as the derivative of the modeled pressure-volume relationship. Graded LBNP to presyncope was used to determine the LBNP tolerance index (LTI). The VWM displayed a better fit to the experimentally induced pressure-volume curve (P &lt; 0.0001). Calf blood pooling was similar in the groups and was not correlated to the LTI (r = 0.204, P = 0.30). Venous compliance was significantly reduced at low venous pressures in women with VVS (P = 0.042) and correlated to the LTI (r = 0.459, P = 0.014) in the low pressure range. No correlation was found between venous compliance at high venous pressures and the LTI. In conclusion, the new VWM accurately adopted the curvilinear pressure-volume curve, providing a valid characterization of venous compliance. Reduced venous compliance at low venous pressures may adversely affect mobilization of peripheral venous blood to the central circulation during hypovolemic circulatory stress in women with VVS.

    Place, publisher, year, edition, pages
    AMER PHYSIOLOGICAL SOC, 2016
    Keywords
    vasovagal syncope; orthostatic intolerance; venous compliance; venous capacitance
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-125296 (URN)10.1152/ajpregu.00362.2015 (DOI)000369058900005 ()26561647 (PubMedID)
    Note

    Funding Agencies|Futurum-The Academy of Health Care; Jonkoping County Council; Medical Research Council of Southeast Sweden; Heart and Lung Foundation

    Available from: 2016-02-24 Created: 2016-02-19 Last updated: 2019-11-11
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  • 6.
    Skoog, Johan
    et al.
    Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine.
    Lindenberger, Marcus
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Ekman, Mikael
    Ekman Biomed Data, Sweden.
    Holmberg, Bengt
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Zachrisson, Helene
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Reduced venous compliance: an important determinant for orthostatic intolerance in women with vasovagal syncope2016In: American Journal of Physiology. Regulatory Integrative and Comparative Physiology, ISSN 0363-6119, E-ISSN 1522-1490, Vol. 310, no 3, p. R253-R261Article in journal (Refereed)
    Abstract [en]

    The influence of lower limb venous compliance on orthostatic vasovagal syncope (VVS) is uncertain. The most widespread technique to calculate venous compliance uses a nonphysiological quadratic regression equation. Our aim was therefore to construct a physiologically derived venous wall model (VWM) for calculation of calf venous compliance and to determine the effect of venous compliance on tolerance to maximal lower body negative pressure (LBNP). Venous occlusion plethysmography was used to study calf volume changes in 15 women with VVS (25.5 +/- 1.3 yr of age) and 15 controls (22.8 +/- 0.8 yr of age). The fit of the VWM and the regression equation to the experimentally induced pressure-volume curve was examined. Venous compliance was calculated as the derivative of the modeled pressure-volume relationship. Graded LBNP to presyncope was used to determine the LBNP tolerance index (LTI). The VWM displayed a better fit to the experimentally induced pressure-volume curve (P &lt; 0.0001). Calf blood pooling was similar in the groups and was not correlated to the LTI (r = 0.204, P = 0.30). Venous compliance was significantly reduced at low venous pressures in women with VVS (P = 0.042) and correlated to the LTI (r = 0.459, P = 0.014) in the low pressure range. No correlation was found between venous compliance at high venous pressures and the LTI. In conclusion, the new VWM accurately adopted the curvilinear pressure-volume curve, providing a valid characterization of venous compliance. Reduced venous compliance at low venous pressures may adversely affect mobilization of peripheral venous blood to the central circulation during hypovolemic circulatory stress in women with VVS.

  • 7.
    Skoog, Johan
    et al.
    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.
    Zachrisson, Helene
    Linköping University, Faculty of Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV). Östergötlands Läns Landsting, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine.
    Lindenberger, Marcus
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Ekman, Mikael
    Ekman Biomed Data AB, Gothenburg, Sweden.
    Ewerman, Lea
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery. Linköping University, Faculty of Health Sciences.
    Calf venous compliance measured by venous occlusion plethysmography: methodological aspects.2015In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 115, no 2, p. 245-56Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Calf venous compliance (C calf) is commonly evaluated with venous occlusion plethysmography (VOP) during a standard cuff deflation protocol. However, the technique relies on two not previously validated assumptions concerning thigh cuff pressure (P cuff) transmission and the impact of net fluid filtration (F filt) on C calf. The aim was to validate VOP in the lower limb and to develop a model to correct for F filt during VOP.

    METHODS: Strain-gauge technique was used to study calf volume changes in 15 women and 10 age-matched men. A thigh cuff was inflated to 60 mmHg for 4 and 8 min with a subsequent decrease of 1 mmHg s(-1). Intravenous pressure (P iv) was measured simultaneously. C calf was determined with the commonly used equation [Compliance = β 1 + 2β 2 × P cuff] describing the pressure-compliance relationship. A model was developed to identify and correct for F filt.

    RESULTS: Transmission of P cuff to P iv was 100 %. The decrease in P cuff correlated well with P iv reduction (r = 0.99, P < 0.001). Overall, our model showed that C calf was underestimated when F filt was not accounted for (all P < 0.01). F filt was higher in women (P < 0.01) and showed a more pronounced effect on C calf compared to men (P < 0.05). The impact of F filt was similar during 4- and 8-min VOP.

    CONCLUSIONS: P cuff is an adequate substitute for P iv in the lower limb. F filt is associated with an underestimation of C calf and differences in the effect of F filt during VOP can be accounted for with the correction model. Thus, our model seems to be a valuable tool in future studies of venous wall function.

  • 8.
    Skoog, Johan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Zachrisson, Helene
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Lindenberger, Marcus
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Reduced compensatory responses to maintain central blood volume during hypovolemic stress in women with vasovagal syncope2017In: American Journal of Physiology. Regulatory Integrative and Comparative Physiology, ISSN 0363-6119, E-ISSN 1522-1490, Vol. 312, no 1, p. R55-R61Article in journal (Refereed)
    Abstract [en]

    Although vasovagal syncope (VVS) is a common clinical condition, the underlying pathophysiology is not fully understood. A decrease in cardiac output has recently been suggested as a factor in orthostatic VVS. The aim was to investigate compensatory mechanisms to maintain central blood volume and venous return during hypovolemic stress in women with VVS. Fourteen VVS women (25.7 +/- 5.0 yr) and 15 matched controls (22.8 +/- 3.2 yr) were investigated. Single-step and graded lower body negative pressure (LBNP) to presyncope were used to create hypovolemic stress. Peripheral mobilization of venous blood from the arm (capacitance response and net capillary fluid absorption) and lower limb blood pooling (calf capacitance response) were evaluated using a volumetric technique. Cardiovascular responses and plasma norepinephrine (P-NE) were measured. Resting P-NE was elevated in VVS women (P amp;lt; 0.01). Despite a similar hypovolemic stimulus, the increase in P-NE was blunted (P amp;lt; 0.01) and the maximal percent increase in total peripheral resistance was reduced (P amp;lt; 0.05) during graded LBNP in VVS women. The arm capacitance response was slower (P amp;lt; 0.05) and reduced in VVS women at higher levels of LBNP (P amp;lt; 0.05). Capillary fluid absorption from extra-to intravascular space was reduced by similar to 40% in VVS women (P amp;lt; 0.05). Accordingly, the reduction in cardiac output was more pronounced (P amp;lt; 0.05). In conclusion, in VVS women, mobilization of peripheral venous blood and net fluid absorption from tissue to blood during hypovolemic stress were decreased partly as a result of an attenuated vasoconstrictor response. This may seriously impede maintenance of cardiac output during hypovolemic stress and could contribute to the pathogenesis of VVS.

  • 9.
    Skoog, Johan
    et al.
    Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine.
    Zachrisson, Helene
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Lindenberger, Marcus
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Slower Lower Limb Blood Pooling Increases Orthostatic Tolerance in Women with Vasovagal Syncope2016In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 7, no 232Article in journal (Refereed)
    Abstract [en]

    Background and Aim: Slower lower limb blood pooling and associated blunted sympathetic activation has been detected in healthy women prone to orthostatic syncope. Whether these findings are true also for patients with vasovagal syncope (WS) is unknown. The aim was to investigate initial blood pooling time (pooling(time), time to 50% of total blood pooling) together with hemodynamic responses and orthostatic tolerance during lower body negative pressure (LBNP) in WS and healthy controls. Methods and Results: Fourteen WS women (25.7 +/- 1.3 years) and 15 healthy women (22.8 +/- 0.8 years) were subjected to single-step and graded LBNP to pre-syncope. Lower limb blood pooling (ml 100 ml(-1)), poolingtime (s), hemodynamic responses and LBNP-tolerance were evaluated. LBNP induced comparable lower limb blood pooling in both groups (controls, 3.1 +/- 0.3; WS, 2.9 +/- 0.3 ml 100 ml(-1), P = 0.70). In controls, shorter pooling(time) correlated to higher LBNP-tolerance (r = -0.550, P amp;lt; 0.05) as well as better maintained stroke volume (r =-0.698, P amp;lt; 0.01) and cardiac output (r = -0.563, P amp;lt; 0.05). In contrast, shorter poolingtime correlated to lower LBNP-tolerance in VVS (r = 0.821, P amp;lt; 0.001) and larger decline in stroke volume (r = 0.611, P 0.05). Furthermore, in controls, shorter poolingtime correlated to baroreflex-mediated hemodynamic changes during LBNP, e.g., increased vasoconstriction (P amp;lt; 0.001). In VVS, poolingtime was not correlated with LBNP-induced baroreceptor unloading, but rather highly correlated to resting calf blood flow (P amp;lt; 0.001). Conclusions: Shorter poolingtime seems to elicit greater sympathetic activation with a concomitant higher orthostatic tolerance in healthy women. The contrasting findings in AS indicate a deteriorated vascular sympathetic control suggesting well-defined differences already in the initial responses during orthostatic stress.

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  • 10.
    Waldreus, Nana
    et al.
    Linköping University, Department of Social and Welfare Studies, Division of Health, Activity and Care. Linköping University, Faculty of Health Sciences.
    Hahn, Robert G.
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping. Sodertalje Sjukhus, Sweden .
    Engvall, Jan
    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.
    Skoog, Johan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    Ewerman, Lea
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Health Sciences.
    Lindenberger, Marcus
    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 Cardiology in Linköping.
    Thirst response to acute hypovolaemia in healthy women and women prone to vasovagal syncope2013In: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 120, p. 34-39Article in journal (Refereed)
    Abstract [en]

    The present study measured self-perceived thirst and plasma angiotensin II (ATII) concentrations during graded hypovolaemic stress, induced by lower body negative pressure (LBNP), to elucidate the dependence of thirst on haemodynamics. A total of 24 women aged between 20 and 36 (mean age, 23) years rated their thirst on a visual analogue scale, graded from 0 to 100, when LBNP of 20,30 and 40 mm Hg was applied. Half of the women had a history of vasovagal syncope (VVS). The results showed that the thirst score increased three-fold when LBNP was applied, from 11 (median; 25th-75th percentiles, 9-25) to 34 (27-53; P andlt; 0.001). The women in the VVS group had twice as great an increase as those without a history of VVS (P andlt; 0.02). The plasma ATII concentration increased significantly in response to LBNP, both in the VVS group and in the control group, but the changes did not correlate with thirst. Application of LBNP decreased systolic and mean arterial pressures, cardiac output and pulse pressure (P andlt; 0.001 for all), but thirst correlated only with increase in heart rate and, independently, with reduction of mean arterial pressure. In conclusion, thirst and ATII increase in response to hypovolaemic stress, but are not statistically related. The haemodynamic parameter that was most strongly related to thirst was tachycardia.

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  • 11.
    Zachrisson, Helene
    et al.
    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 Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Nelzén, Oskar
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Lassvik, Claes
    Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Faculty of Medicine and Health Sciences.
    Skoog, Johan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Estimation of Superficial Venous Reflux with Duplex Ultrasound and Foot Volumetry2019In: Juniper Online Journal of Case Studies, ISSN 2476-1370, Vol. 10, no 1, p. 1-5, article id 555776Article in journal (Refereed)
    Abstract [en]

    Objective: To evaluate quantitative duplex ultrasound (DUS) parameters of reflux in patients with isolated great saphenous vein insufficiency.

    Methods: 20 limbs were studied. DUS derived reflux time (RT, sec), peak reflux velocity (PRV, cm/s) and reflux volume flow (ml/min) were evaluated and related to expelled volume (EV, ml) and half refilling time (T50, sec) measured by water-based foot volumetry with and without compression of superficial veins.

    Results: Reflux volume flow correlated significantly to all hemodynamic parameters assessed by foot volumetry, i.e., EV (p = 0.003), ΔEV (p = 0.006), T50 (p = 0.004) and ΔT50 (p = 0.011). PRV displayed a weaker correlation to foot volumetry parameters EV (p = 0.027) and T50 (p = 0.008). No significant correlation was found between RT and foot volumetry.

    Conclusion: These results indicate that reflux volume flow may be a potential parameter in future attempts to quantify reflux using DUS in patients with isolated great saphenous vein insufficiency.

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