Preejection period as a sympathetic activity index: a role of confounding factors

Title:

Preejection period as a sympathetic activity index: a role of confounding factors

Creator:

Krohova, J., Czippelova, B., Turianikova, Z., Želmíra Lazárová, Ingrid Tonhajzerová, and Michal Javorka

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:83a2be82-921a-4754-986e-80caec66004e
uuid:83a2be82-921a-4754-986e-80caec66004e
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, preejection period, impedance cardiography, head-up tilt, mental stress, thoracic fluid content, systemic vascular resistance, 14, and 612

Type:

article, články, journal articles, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

n previous studies, one of the systolic time intervals - preejection period (PEP) - was used as an index of sympathetic activity reflecting the cardiac contractility. However, PEP could be also influenced by several other cardiovascular variables including preload, afterload and diastolic blood pressure (DBP). The aim of this study was to assess the behavior of the PEP together with other potentially confounding cardiovascular system characteristics in healthy humans during mental and orthostatic stress (head-up tilt test - HUT). Forty-nine healthy volunteers (28 females, 21 males, mean age 18.6 years (SD=1.8 years)) participated in the study. We recorded finger arterial blood pressure by volume-clamp method (Finome ter Pro, FMS, Netherlands), PEP, thoracic fluid content (TFC) - a measure of preload, and cardiac output (CO) by impedance cardiography (CardioScreen ®2000, Medis, Germany). Systemic vascular resistance (SVR) - a measure of afterload - was calculated as a ratio of mean arterial pressure and CO. We observed that during HUT, an expected decrease in TFC was accompanied by an increase of PEP, an increase of SVR and no significant change in DBP. During mental stress, we observed a decrease of PEP and an increase of TFC, SVR and DBP. Correlating a change in assessed measures (delta values) between mental stress and previous supinerest, we found that ΔPEP correlated negatively with ΔCO and positively with ΔSVR. In orthostasis, no significant correlation between ΔPEP and ΔDBP, ΔTFC, ΔCO, ΔMBP or ΔSVR was found. We conclude that despite an expected increase of sympathetic activity during both challenges, PEP behaved differently indicating an effect of other confounding factors. To interpret PEP values properly, we recommend simultaneously to measure other variables influencing this cardiovascular measure., J. Krohova, B. Czippelova, Z. Turianikova, Z. Lazarova, I. Tonhajzerova, M. Javorka., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Source:

Physiological research | 2017 Volume:66 | Number:Suppl 2

Harvested from:

CDK

Metadata only:

false