Effect of posture on baroreflex sensitivity in healthy subjects |
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Authors: | J. Hartikainen,E. Vanninen,E. L nsimies |
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Affiliation: | J. Hartikainen,E. Vanninen,E. Länsimies |
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Abstract: | Summary. In this study we investigated whether body position has significant effects on baroreflex sensitivity in healthy subjects. Baroreflex sensitivity was calculated from pressure overshoot after the release of a Valsalva strain in the supine and sitting positions in 10 subjects. At rest, no difference was found in supine and sitting mean R-R intervals (837±82 and 858±86 ms, respectively), whereas systolic and diastolic blood pressures were lower in the supine position (111.3±24.6 vs. 141.2±12.6 mmHg, P<0.01 and 54.8±14.7 vs. 75.6±13.4 mmHg, P<0.001, respectively). Baroreflex sensitivity in the supine (9.0±4.1 ms±mmHg-1) and sitting positions (8.8±4.9 msXmmHg-1) did not differ significantly from each other. The correlation between supine and sitting baroreflex sensitivity was 0.96 (P<0.001) and in 9 out of 10 subjects the discrepancy between supine and sitting baroreflex sensitivity was <2.0 ms±mmHg-1. We conclude that baroreflex sensitivity measured in the supine and sitting positions do not differ significantly from each other. |
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Keywords: | autonomic nervous system blood pressure heart rate Valsalva manoeuvre |
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