| 1. |
- Henriksen, Egil, et al.
(författare)
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Left ventricular end-diastolic geometrical adjustments during exercise in endurance athletes
- 2008
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 28:2, s. 76-80
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Tidskriftsartikel (refereegranskat)abstract
- The increase in left ventricular (LV) end-diastolic volume has recently been shown to explain more than 70% of the increase in stroke volume during upright exercise in endurance athletes. As the end-diastolic volume enhancement not could be explained by an increase in axial cavity length an augmentation in LV short-axis diameters is to be expected. To investigate LV end-diastolic geometrical alterations during exercise, 15 endurance athletes were examined using contrast exercise echocardiography. LV end-diastolic short-axis diameters were made from apical views at several LV cavity levels. From upright rest to upright exercise the LV end-diastolic internal cavity measurements increased significantly. During exercise, the LV cavity became geometrically more spherical with the largest increase in the LV end-diastolic short-axis cavity diameters in the mid and apical parts of the left ventricle. The LV internal long axis showed significant increase from rest to exercise but the absolute increase was small.
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| 2. |
- Selmeryd, Jonas, et al.
(författare)
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Impact of left ventricular geometry on long-term survival in elderly men and women
- 2014
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 34:6, s. 442-448
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Tidskriftsartikel (refereegranskat)abstract
- Background: Adverse loading conditions and cardiac injury lead to remodelling of the heart into different patterns of left ventricular (LV) geometry. Geometry can be classified into LV hypertrophy (LVH), concentric remodelling (CR) or normal geometry (NG). The prognostic implications of the different geometric patterns have been extensively studied in middle-aged subjects, but data are scarcer for elderly populations. Methods: From a community-based random sample of 75-year-old men and women, subjects with normal LVEF were selected (n = 303). All-cause and cardiovascular mortality was analysed by LV geometry with Cox regression (unadjusted and adjusted for sex, prevalent hypertension, smoking, diabetes and prevalent ischaemic heart disease). Median follow-up time was 9.9 years. Results: Prevalence of CR and LVH was 19% and 17%, respectively. Hazard ratios (HRs) for CR were 0.93 (95% CI 0.54-1.58) for all-cause and 1.13 (0.48-2.65) for cardiovascular mortality. HRs for LVH were 2.01 (1.30-3.10) for all-cause and 3.55 (1.89-6.67) for cardiovascular mortality. As non-proportionality was present in the form of an increasing hazard for LVH, we partitioned the follow-up time at the median event time (approximately 7 years) and performed Cox regression separately within each time period. HRs for LVH during the first period were 1.23 (0.63-2.42) for all-cause and 1.79 (0.69-4.65) for cardiovascular mortality, while HRs for the second period were 3.06 (1.73-5.41) for all-cause and 6.60 (2.82-15.39) for cardiovascular mortality. Conclusion: In this community-based sample of 75-year-old men and women with normal LVEF, LVH was associated with an adverse prognosis during long-term follow-up, whereas CR was not.
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| 3. |
- Sundstedt, Milena, et al.
(författare)
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Echocardiographic doppler assessments of left ventricular filling and ejection during upright exercise in endurance athletes
- 2007
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 27:1, s. 36-41
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Tidskriftsartikel (refereegranskat)abstract
- Doppler echocardiography was used to describe left ventricular filling and ejection during upright bicycle exercise in 24 healthy male endurance athletes. The transmitral pressure gradient was estimated and isovolumetric relaxation, filling and ejection time and transmitral and aortic flow velocities were measured at rest and during exercise. From rest to peak exercise (at a heart rate of 160 bpm), the mean left ventricular filling time was shortened by 73%, the ejection time by 31%, while the isovolumetric relaxation time was shortened by 62%. At peak exercise, the maximum aortic flow velocity almost doubled and the maximum transmitral flow velocity more than doubled, with a tenfold increase in the mean transmitral pressure gradient. The increase was significant (P<0·001) at each level of exercise. The left ventricular filling rate measured as volume per time was 185 ± 62 ml s−1 at rest and it increased to 986 ± 192 ml s−1 at peak exercise. This study demonstrates large changes in diastolic filling indices during upright exercise and it shows that the heart is able to increase its filling rate five times from rest to peak exercise.
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| 4. |
- Sundstedt, Milena, 1969-
(författare)
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Left Ventricular Dynamics During Exercise in Endurance Athletes
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Large quantities of data have described left ventricular adaptation to endurance training, but basic concepts on left ventricular performance during exercise remain controversial. In this thesis, we present the results of studies of left ventricular dynamics during exercise in 89 endurance-trained athletes.Using radionuclide ventriculography, 35 female and 30 male endurance athletes were studied in supine position. During supine exercise at 70% of the age-expected maximal heart rate, the adjustments in left ventricular volumes were small, suggesting a high preload before exercise. Stroke volume increased by changes in the left ventricular end-diastolic volumes but no changes were observed in the end-systolic volumes. Moreover, no significant differences were noted between male and female athletes.Contrast echocardiography was utilized when 24 male endurance athletes were studied during upright exercise. An almost linear increase in stroke volume was seen from upright rest to upright exercise at a heart rate of 160 beats per minute. Stroke volume increased by an almost linear increase in end-diastolic volume and showed an initial small decrease in end-systolic volume. The left ventricular cavity became geometrically more spherical with the largest increase in the left ventricular end-diastolic short-axis cavity diameters in the mid and apical part of the left ventricle. Left ventricular long-axis length obtained from the epicardial apex to the middle of the mitral annulus at end-diastole showed no significant change from rest to exercise. The mitral annulus motion contributed to more than 50% of the stroke volume during exercise with no significant difference between septal and lateral annular motion at peak exercise. Major changes were observed in left ventricular filling indices during upright exercise. The mean transmitral pressure gradient showed a linear increase and increased several times as the mean diastolic time decreased, with large reductions in mean left ventricular filling time. Despite the shortened filling time, the heart was able to increase the filling rate (measured as volume per time) five times. This observation verifies that the heart has large reserves at rest and reveals the increase in capacity during exercise.
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| 5. |
- Sundstedt, Milena, et al.
(författare)
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Left ventricular volume changes during supine exercise in young endurance athletes
- 2003
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772 .- 1365-201X. ; 177:4, s. 467-472
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The primary objective of the study was to measure the relative left ventricular volumes and the changes in left ventricular ejection fraction during supine position from rest to exercise in young endurance athletes. The secondary objective was to examine if there were gender differences regarding the volume reply and ejection fraction with exercise.Method: Sixty-five (35 female and 30 males) young healthy Swedish orienteers participated in the study. Left ventricular volume and ejection fraction changes between rest and submaximal supine bicycle exercise were measured with radionuclide ventriculography.Results: The mean left ventricular end-diastolic volume increased by 13% (P < 0.001) but there was no change in end-systolic volume. Stroke volume was found to increase by 21% (P < 0.001). Left ventricular ejection fraction increased significantly (>0.04 units) in 54% of the athletes from rest to exercise; 5% of the athletes showed a decrease in ejection fraction. A negative correlation was found between ejection fraction at rest and the difference in ejection fraction from rest to exercise (r = −0.38, P = 0.002). There were no gender differences in the left ventricular volume changes or ejection fraction.Conclusion: During submaximal supine exercise, the adjustments in cardiac volumes in endurance athletes were small. There were no gender disparities concerning the left ventricular volume reply during exercise.
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| 6. |
- Sundstedt, Milena, et al.
(författare)
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Mitral annular excursion during exercise in endurance athletes
- 2008
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 28:1, s. 27-31
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to quantify the left ventricular (LV) longitudinal motion during exercise at rest and during upright exercise in 24 healthy male endurance athletes. By using M-mode and two-dimensional echocardiography, the relative mitral annular motion and the absolute LV longitudinal axis was measured at end-diastole and end-systole at rest and during exercise. From rest to peak exercise at a heart rate of 160 beats per minute (bpm) the mitral annular motion increased in the septal and lateral annular borders by 68% and 49% respectively. At rest, mitral annular excursion was significantly (13%) higher in the lateral than in the septal wall but at peak exercise at a heart rate of 160 bpm there was no difference between the septal and lateral annular motion. The total end-diastolic LV axial length did not increase from rest to peak exercise. In conclusion, during upright exercise, mitral annular motion increased significantly with no difference between the septal and lateral annular excursion at peak exercise. The absolute increase in mitral annular motion during exercise was explained by a decrease in axial end-systolic length.
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