Active standing and passive tilting similarly reduce the slope of spontaneous baroreflex in healthy subjects

Title:

Active standing and passive tilting similarly reduce the slope of spontaneous baroreflex in healthy subjects

Creator:

Bahjaoui-Bouhaddi, M., Henriet, M.-T., Cappelle, S., Dumoulin, G., and Regnard, J.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:55765732-3314-42f4-b41e-f98a9f2cd7fe
uuid:55765732-3314-42f4-b41e-f98a9f2cd7fe

Subject:

baroreflex slope, spontaneous baroreflex, head-up tilt, and standing

Type:

article, model:article, and TEXT

Description:

Non-invasive assessment of the sensitivity of cardiac baroreflex was performed by recording each RR-interval and each blood pressure cycle (Finapres®). In sequences of at least three cardiac cycles in which systolic blood pressure and RR-interval had changed in the same direction, the slope of linear regression of RR duration as a function of the change in systolic arterial pressure was taken for estimating the sensitivity of the spontaneous cardiac baroreflex. This technique was used in healthy humans to examine how a postural change from supine to upright by either active standing up or 60° head-up tilting modified the sensitivity of the spontaneous baroreflex. We observed that the slope of the spontaneous baroreflex averaged 14.6 ±2 ms.mm Hg_1 during rest in the supine position, and decreased to 7.8 ± 1.2 ms.mm Hg"1 (p<0.05) after active standing, while the number of sequences was significantly increased in the upright as compared to the supine position. Head-up tilting by 60° led to values similar to those following active standing. The adjustment of baroreflex slope to either postural change occurred in a few seconds, so that posture-characteristic values were obtained from five-minute records. We conclude that non- invasive recording of spontaneous sequences of related changes in blood pressure and RR-interval during several minutes provides reproducible values of the slope of cardiac baroreflex in the supine and upright position. This easy and reliable determination of the sensitivity of the cardiac baroreflex might prove to be useful when assessment of baroreflex function is needed.

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 1998 Volume:47 | Number:4

Harvested from:

CDK

Metadata only:

false