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- Shlimon, Kristian, et al.
(författare)
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Radial artery lumen diameter and intima thickness in patients with abdominal aortic aneurysm
- 2022
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Ingår i: JVS-Vascular Science. - : Elsevier Inc.. - 2666-3503. ; 3, s. 274-284
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Abdominal aortic aneurysm (AAA) is associated with dilatation of central elastic arteries, while it is uncertain whether peripheral muscular arteries are affected. The aim of this study was to investigate radial artery diastolic lumen diameter (LD), wall thickness, and circumferential wall stress (CWS) in patients with AAA. Methods: We included 130 men with AAA (mean age, 70.4 ± 3.5 years) and 61 men without AAA (mean age, 70.5 ± 3.2 years) in the study. High-frequency ultrasound examination (50 MHz) was used to measure radial artery diameter, wall thickness, and CWS was calculated. Results: Men with AAA exhibited smaller radial artery LD (2.34 ± 0.42 mm vs 2.50 ± 0.38 mm; P <.01), thicker intima (0.094 ± 0.024 mm vs 0.081 ± 0.018 mm; P <.001), similar intima-media (0.28 ± 0.05 vs 0.26 ± 0.05 mm; P = NS), and lower CWS (42.9 ± 10.2 kPa vs 48.6 ± 11.4 kPa; P <.001), compared with controls. Subgroup analyses including all patients showed smaller LD and thicker intima in patients on statin therapy versus no statin therapy and current/ex-smoking versus never smoking. Individuals with hypertension versus no hypertension also presented with thicker intima, but with no difference in LD. Conclusions: AAAs demonstrated a smaller LD and thicker intima in the radial artery, in contrast with the theory of a general dilating diathesis of the arteries. Apart from AAA, other factors such as atherosclerosis, smoking habits, and hypertension might also be determinants of radial artery caliber and thickness. Clinical Relevance: The clinical relevance of this study is the added insight into the pathophysiology of abdominal aortic aneurysm (AAA). Today, the management of AAA is focused on reduction of general cardiovascular risk factors and treatment is based on surgical approaches when the AAA is already manifest. By shedding light on unknown pathophysiological aspects of AAA, it will eventually be possible to develop targeted pharmacological treatments to prevent the formation of AAA, to halt disease progression, and to find early cardiovascular markers of AAA. © 2022 Society for Vascular Surgery
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| 3. |
- Lindenberger, Marcus, 1975-
(författare)
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Cardiovascular responses to hypovolemic circulatory stress in women : With special reference to venous compliance and capacitance
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Acute haemorrhage is a leading cause of death in trauma. Young women (YW) seem more susceptible to hypovolemic circulatory stress than young men (YM), but the underlying mechanisms are not clear. Elderly subjects are more vulnerable to haemorrhage, with a decreased defence of central blood volume in elderly men, but the defence has not been evaluated in elderly women (EW). The aims were to assess differences in cardiovascular responses to hypovolemic circulatory stress, emphasizing compensatory mechanisms to maintain central blood volume in YW, EW and in women prone to vaso‐vagal reaction (VW).Lower body negative pressure (LBNP) was used as a model for haemorrhage and to create acute hypovolemic stress. Volumetric techniques were used to assess venous compliance, capacitance and capillary fluid exchange both caused by LBNP in the calf and the response to maintain central blood volume.LBNP induced a comparable hypovolemic stimulus in YW and YM, with lower calf venous compliance and capacitance but higher net capillary fluid filtration in YW. YW responded with smaller vasoconstriction without association between P‐NE and peripheral vascular resistance in contrast to YM. Venous capacitance response was decreased with time in YW. Further, net capillary fluid absorption from peripheral tissues to central circulation was decreased in YW in response to hypovolemic stress. All in all, this indicates less efficiency to defend central blood volume in young women.Calf venous compliance and capacitance was maintained in EW compared to YW but capillary filtration was decreased, implying reduced capillary function with age. With increasing transmural pressures however, filtration and capillary filtration coefficient (CFC) increased indicating increased capillary susceptibility to transmural pressure load in dependent regions with age. Heart rate increase was attenuated in EW while peripheral vascular conductance was maintained suggesting reduced cardiovagal baroreceptor function in response to hypovolemia with age. Venous capacitance response and fluid absorption from peripheral tissues to central circulation were decreased with age, indicating less efficiency to defend central blood volume.LBNP induced a slower hypovolemic stimulus in VW compared with nonvagal women. Further, the cardiopulmonary baroreflex was less efficient, and the venous capacitance response from peripheral tissues to central circulation was decreased, which may explain their susceptibility to orthostatic challenge.
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| 4. |
- Lindenberger, Marcus, 1975-, et al.
(författare)
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Decreased capillary filtration but maintained venous compliance in the lower limb of aging women
- 2007
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Ingår i: American Journal of Physiology. Heart and Circulatory Physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 293, s. H3568-H3574
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Tidskriftsartikel (refereegranskat)abstract
- There are sex-related differences in venous compliance and capillary filtration in the lower limbs, which to some extent can explain the susceptibility to orthostatic intolerance in young women. With age, venous compliance and capacitance are reduced in men. This study was designed to evaluate age-related changes in venous compliance and capillary filtration in the lower limbs of healthy women. Included in this study were 22 young and 12 elderly women (23.1 ± 0.4 and 66.4 ± 1.4 yr). Lower body negative pressure (LBNP) of 11, 22, and 44 mmHg created defined transmural pressure gradients in the lower limbs. A plethysmographic technique was used on the calf to assess venous capacitance and net capillary filtration. Venous compliance was calculated with the aid of a quadratic regression equation. No age-related differences in venous compliance and capacitance were found. Net capillary filtration and capillary filtration coefficient (CFC) were lower in elderly women at a LBNP of 11 and 22 mmHg (0.0032 vs. 0.0044 and 0.0030 vs. 0.0041 ml·100 ml–1·min–1·mmHg–1, P < 0.001). At higher transmural pressure (LBNP, 44 mmHg), CFC increased by 1/3 (0.010 ml·100 ml–1·min–1·mmHg–1) in the elderly (P < 0.001) but remained unchanged in the young women. In conclusion, no age-related decrease in venous compliance and capacitance was seen in women. However, a decreased CFC was found with age, implying reduced capillary function. Increasing transmural pressure increased CFC in the elderly women, indicating an increased capillary susceptibility to transmural pressure load in dependent regions. These findings differ from earlier studies on age-related effects in men, indicating sex-specific vascular aging both in the venous section and microcirculation.
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| 6. |
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| 7. |
- Lindenberger, Marcus, 1975-, et al.
(författare)
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Lower capacitance response and capillary fluid absorption in women to defend central blood volume in response to acute hypovolemic circulatory stress
- 2008
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Ingår i: American Journal of Physiology. Heart and Circulatory Physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 295, s. H867-H873
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Tidskriftsartikel (refereegranskat)abstract
- Acute hemorrhage is a leading cause of death in trauma, and women are more susceptible to hypovolemic circulatory stress than men. The mechanisms underlying the susceptibility are not clear, however. The aim of the present study was to examine the compensatory mechanisms to defend central blood volume during experimental hypovolemia in women and men. Twenty-two women (23.1 ± 0.4 yr) and 16 men (23.2 ± 0.5 yr) were included. A lower body negative pressure (LBNP) of 11–44 mmHg induced experimental hypovolemic circulatory stress. The volumetric technique was used to assess the capacitance response (redistribution of peripheral venous blood to the central circulation) as well as to assess net capillary fluid transfer from tissue to blood in the arm. Plasma norepinephrine (NE) and forearm blood flow were measured before and during hypovolemia, and forearm vascular resistance (FVR) was calculated. LBNP created comparable hypovolemia in women and men. FVR increased less in women during hypovolemic stress, and no association between plasma NE and FVR was seen in women (R2 = 0.01, not significant), in contrast to men (R2 = 0.59, P < 0.05). Women demonstrated a good initial capacitance response, but this was not maintained with time, in contrast to men [e.g., decreased by 24 ± 4% (women) vs. 4 ± 5% (men), LBNP of 44 mmHg, P < 0.01], and net capillary fluid absorption from tissue to blood was lower in women (0.086 ± 0.007 vs. 0.115 ± 0.011 ml·100 ml–1·min–1, P < 0.05). In conclusion, women showed impaired vasoconstriction, reduced capacitance response with time, and reduced capillary fluid absorption during acute hypovolemic circulatory stress, indicating less efficiency to defend central blood volume than men.
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| 8. |
- Lindenberger, Marcus, 1975-, et al.
(författare)
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Pericardiocentesis guided by 2-D echocardiography : The method of choice for treatment of pericardial effusion
- 2003
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 253:4, s. 411-417
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Tidskriftsartikel (refereegranskat)abstract
- Background. Percutaneous pericardiocentesis guided by 2-D echocardiography has been used at Link÷ping Heart Centre since 1983. Aim. To evaluate our experience of this method including a follow-up and also to determine the aetiology of pericardial effusion. Methods. A retrospective study including 120 of 252 consecutive patients punctured. Results. The two most common aetiologies were cardiac surgery (77% valve surgery), followed by malignant disease. The postsurgical effusions became clinically important a median of 12 days after surgery (range 0-56 days). The median survival in the group with malignant disease was 89 days (30-day survival 87%, 1-year survival 10%). Indwelling catheter was used in 93% of the patients. There was no mortality but one patient needed a second pericardiocentesis after an accidental puncture of the right ventricle. Nine patients had rhythm aberrations. Recurring effusion that needed puncture was seen in 8%. Conclusion. Pericardiocentesis guided by 2-D echocardiography is a safe and efficient method to treat pericardial effusion and also valuable as palliative treatment for patients with malignant aetiology of the effusion.
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| 9. |
- Lindenberger, Marcus, 1975-, et al.
(författare)
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Reduced defense of central blood volume during acute hypovolemic circulatory stress in aging women
- 2012
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Ingår i: Shock. - : Lippincott Williams & Wilkins. - 1073-2322 .- 1540-0514. ; 37:6, s. 579-585
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Tidskriftsartikel (refereegranskat)abstract
- Elderly men respond with decreased defense of central blood volume during hypovolemic stress, but this response has not been evaluated with age in women. The aim was to examine the compensatory mechanisms to defend central blood volume during experimental hypovolemia in elderly compared to young women. Cardiovascular responses in 34 women, 12 elderly (66.4±1.4 yr) and 22 young (23.1±0.4 yr) were studied during experimental hypovolemic circulatory stress induced by lower body negative pressure (LBNP) of 11-44 mmHg. Volumetric technique was used to assess the capacitance response (redistribution of peripheral venous blood to the central circulation) as well as to assess net capillary fluid transfer from tissue to blood in the arm. LBNP created comparable hypovolemia in elderly and young women. Heart rate increased less in elderly women (LBNP of 44 mmHg: 20±2 vs. 37±4 %, P < 0.01), but with similar decrease in forearm vascular conductance (FVC). Mobilization of capacitance blood from the peripheral circulation was both slower and decreased by ~60 % in elderly, and net capillary fluid absorption from surrounding tissues was reduced by ~40 % (LBNP of 44 mmHg). In conclusion, during acute hypovolemic circulatory stress elderly women responded with less increase in heart rate but with an equal change in FVC, implying decreased cardiovagal baroreceptor sensitivity. Furthermore, both capacitance response and net capillary fluid absorption were reduced, indicating less efficiency to defend central blood volume in elderly than in young women.
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| 10. |
- Lindenberger, Marcus, 1975-, et al.
(författare)
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Sex-related effects on venous compliance and capillary filtration in the lower limb
- 2007
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Ingår i: American Journal of Physiology. Regulatory Integrative and Comparative Physiology. - : American Physiological Society. - 0363-6119 .- 1522-1490. ; 292, s. R852-R859
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies in humans have suggested sex differences in venous compliance of the lower limb, with lower compliance in women. Capillary fluid filtration could, however, be a confounder in the evaluation of venous compliance. The venous capacitance and capillary filtration response in the calves of 12 women (23.2 ± 0.5 years) and 16 men (22.9 ± 0.5 years) were studied during 8 min lower body negative pressure (LBNP) of 11, 22, and 44 mmHg. Calf venous compliance is dependent on pressure and was determined using the first derivative of a quadratic regression equation that described the capacitance-pressure relationship [compliance = 1 + (2·2· transmural pressure)]. We found a lower venous compliance in women at low transmural pressures, and the venous capacitance in men was increased (P < 0.05). However, the difference in compliance between sexes was reduced and not seen at higher transmural pressures. Net capillary fluid filtration and capillary filtration coefficient (CFC) were greater in women than in men during LBNP (P < 0.05). Furthermore, calf volume increase (capacitance response + total capillary filtration) during LBNP was equivalent in both sexes. When total capillary filtration was not subtracted from the calf capacitance response in the calculation of venous compliance, the sex differences disappeared, emphasizing that venous compliance measurement should be corrected for the contribution of CFC.
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