| 1. |
- Damm, S., et al.
(författare)
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Wall motion abnormalities in male elite orienteers are aggravated by exercise
- 1999
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Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 19:2, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- During the period 1979-92, 16 (15 men and one woman) sudden unexpected cardiac deaths occurred among young Swedish orienteers. This finding indicated a sharp increase in the death rate of orienteers, and necropsy demonstrated that myocarditis was a common histopathological finding. Therefore, an extensive non-invasive cardiac investigation was performed. A total of 59 male élite orienteers (mean age 23 years) and 36 cross-country skiers and middle-distance runners (mean age 22 years), serving as controls, were examined by both echocardiography at rest and radionuclide ventriculography at rest and during exercise. Wall motion abnormalities were found in eight orienteers using echocardiography. The purpose of this study was to examine whether the group of orienteers with wall motion abnormalities found using echocardiography had a smaller increase in ejection fraction from rest to exercise using radionuclide ventriculography than the rest of the orienteers and the controls, indicating an aggravation of the wall motion abnormalities during exercise. There were no significant differences in the ejection fraction at rest between the groups. In the orienteers with wall motion abnormalities (group 1), 62% (five out of eight) had less than a 0.05 unit increase in left ventricular ejection fraction compared with 27% (14 out of 51) of the remaining orienteers (group 2) and 19% (7 out of 36) of the controls (group 3). A comparison of athletes in group 1 with those in groups 2 and 3 combined revealed a statistically significant difference (P < 0.05). The divergent response in left ventricular ejection fraction during exercise suggests an aggravation of the wall motion abnormalities with exercise. Both the echocardiographic and the radionuclide ventriculographic findings indicate that the orienteers in group 1 had concealed left ventricular damage.
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| 4. |
- Henriksen, Egil, et al.
(författare)
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An echocardiographic study of right and left ventricular adaptation to physical exercise in elite female orienteers
- 1999
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 20:4, s. 309-316
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A considerable body of echocardiographic studies has described how athletic training induces morphological adaptation of the left ventricle in male endurance athletes, but only a few studies have described left ventricular adaptation in female endurance athletes. In contrast to changes in the left ventricle far less attention has been directed towards right ventricular changes due to extensive physical exercise. The purpose of this study was to obtain normal values and to determine if there are any differences in right and left ventricular cavity and wall dimensions between female orienteers and females with a mainly sedentary lifestyle. METHODS: Echocardiography was performed in 42 highly trained elite female orienteers and 32 healthy female students with a predominantly sedentary lifestyle. The 74 females had no history of cardiac disease, a normal electrocardiogram and showed no echocardiographic abnormalities. M-mode and two-dimensional measurements of the right and left ventricular cavity and wall were obtained in elite orienteers and sedentary females. For the right ventricle and wall, multiple cross-sections were used and measurements were obtained from the right ventricular inflow and outflow tract. RESULTS: The left ventricular end-diastolic cavity dimension and the left ventricular wall thickness were significantly greater in the athletes compared with the sedentary controls. The right ventricular inflow tract measurements were all significantly greater in the orienteers compared with the controls but the right ventricular outflow tract measurements were comparable in the study groups. The right ventricular wall thickness, calculated as the mean of three different wall measurements was an average of 13% greater in the athletes compared with the sedentary controls. CONCLUSION: This study suggests symmetrical cardiac enlargement with a concomitant increase in both the right and left ventricular wall, probably reflecting the increased haemodynamic loading in the female athletes.
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| 5. |
- Henriksen, Egil, et al.
(författare)
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Echocardiographic right and left ventricular measurements in male elite endurance athletes
- 1996
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 17:7, s. 1121-1128
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Tidskriftsartikel (refereegranskat)abstract
- Echocardiography was used to assess normal values in the right and left ventricular cavity and wall in 127 male elite endurance athletes. M-mode and two dimensional measurements of left ventricle and left and right atria were also obtained. All subjects were high-performance orienteers, cross-country skiers and middle-distance runners. They all had a normal electrocardiogram at rest and no echocardiographic evidence of heart disease. With the use of multiple right ventricular cross-sections and two-dimensional measurements, we found a significantly greater right ventricular inflow tract and right and left atrial measurements in endurance athletes compared with earlier studies of normal, active subjects. The right ventricular free wall was slightly thicker than reported in normal active subjects but the differences were small. Left ventricular diastolic diameter was consistent with previous reports of endurance athletes. Of the 127 subjects, 13% had left ventricular wall thickness above 13 mm but none of the athletes had wall thickness above 15 mm. These data suggest that cardiac enlargement occurs symmetrically in both right and left cavities, probably reflecting increased haemodynamic loading, a mechanism by which athletes sustain a high cardiac output during exercise.
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| 6. |
- Jonason, T., et al.
(författare)
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Menopause is associated with the stiffness of the common carotid artery in 50-year-old women
- 1998
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Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 18:2, s. 149-155
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Tidskriftsartikel (refereegranskat)abstract
- To determine if menopause has an effect on the elasticity of the arteries, the stiffness index of the common carotid artery was studied in 84 premenopausal and 139 post-menopausal women. The study group was age-homogeneous, all women being 50 years of age. There were no significant differences between pre- and post-menopausal women regarding atherosclerosis, when measured as the number of subjects with plaques or intimal-medial thickness. The diameter of the common carotid artery was significantly larger in post-menopausal women. The diameter was correlated to measurements of body size which did not, however, differ between the two groups. The mean stiffness indexes were 4.99 +/- 1.02 and 5.38 +/- 1.21 in the pre- and post-menopausal groups respectively (P < 0.05). In a multivariate analysis, menopause (P < 0.05), and also serum insulin levels (P < 0.01) and smoking (P < 0.05) were found to have independent significant associations to the stiffness index. In conclusion, menopause is associated with reduced elasticity of the carotid arteries in 50-year-old women.
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| 7. |
- Jonsson, T, et al.
(författare)
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Nonequilibrium dynamics in a three-dimensional spin glass
- 1999
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Ingår i: PHYSICAL REVIEW B-CONDENSED MATTER. - 0163-1829. ; 59:13, s. 8770-8777
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Tidskriftsartikel (refereegranskat)abstract
- Nonequilibrium dynamics in a AE(11% Mn) spin glass has been studied by low frequency ac-susceptibility and magnetic relaxation experiments. The results unequivocally show that spin structures that memorize the cooling process are imprinted in the system.
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| 8. |
- Jonsson, T, et al.
(författare)
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Relaxation of the field-cooled magnetization of an Ising spin glass
- 1999
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Ingår i: PHYSICAL REVIEW B-CONDENSED MATTER. - : AMERICAN PHYSICAL SOC. - 0163-1829. ; 59:14, s. 9402-9407
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Tidskriftsartikel (refereegranskat)abstract
- The time and temperature dependence of the field-cooled magnetization of a three-dimensional Ising spin glass Fe0.5Mn0.5TiO3 has been investigated. The temperature and cooling rate dependence is found to exhibit memory phenomena that can be related to the
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