Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Jan 25:9:25.
doi: 10.3389/fphys.2018.00025. eCollection 2018.

Relationship between Aortic Compliance and Impact of Cerebral Blood Flow Fluctuation to Dynamic Orthostatic Challenge in Endurance Athletes

Affiliations

Relationship between Aortic Compliance and Impact of Cerebral Blood Flow Fluctuation to Dynamic Orthostatic Challenge in Endurance Athletes

Tsubasa Tomoto et al. Front Physiol. .

Abstract

Aorta effectively buffers cardiac pulsatile fluctuation generated from the left ventricular (LV) which could be a mechanical force to high blood flow and low-resistance end-organs such as the brain. A dynamic orthostatic challenge may evoke substantial cardiac pulsatile fluctuation via the transient increases in venous return and stroke volume (SV). Particularly, this response may be greater in endurance-trained athletes (ET) who exhibit LV eccentric remodeling. The aim of this study was to determine the contribution of aortic compliance to the response of cerebral blood flow fluctuation to dynamic orthostatic challenge in ET and age-matched sedentary (SED) young healthy men. ET (n = 10) and SED (n = 10) underwent lower body negative pressure (LBNP) (-30 mmHg for 4 min) stimulation and release the pressure that initiates a rapid regain of limited venous return and consequent increase in SV. The recovery responses of central and middle cerebral arterial (MCA) hemodynamics from the release of LBNP (~15 s) were evaluated. SV (via Modeflow method) and pulsatile and systolic MCA (via transcranial Doppler) normalized by mean MCA velocity (MCAv) significantly increased after the cessation of LBNP in both groups. ET exhibited the higher ratio of SV to aortic pulse pressure (SV/AoPP), an index of aortic compliance, at the baseline compared with SED (P < 0.01). Following the LBNP release, SV was significantly increased in SED by 14 ± 7% (mean ± SD) and more in ET by 30 ± 15%; nevertheless, normalized pulsatile, systolic, and diastolic MCAv remained constant in both groups. These results might be attributed to the concomitant with the increase in aortic compliance assessed by SV/AoPP. Importantly, the increase in SV/AoPP following the LBNP release was greater in ET than in SED (P < 0.01), and significantly correlated with the baseline SV/AoPP (r = 0.636, P < 0.01). These results suggest that the aortic compliance in the endurance athletes is able to accommodate the additional SV and buffer the potential increase in pulsatility at end-organs such as the brain.

Keywords: aortic compliance; cerebral hemodynamics; endurance training; lower body negative pressure stimulation; pulsatile blood flow.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Typical response of radial arterial blood pressure (ABP), transcranial Doppler measured middle cerebral artery blood flow velocity (MCA v) and chamber pressure during baseline (0 mmHg), LBNP-30 mmHg, and after release LBNP.
Figure 2
Figure 2
The changes in stroke volume and aortic compliance (SV/AoPP) after the release of LBNP up to 15 s.
Figure 3
Figure 3
Relationship between the baseline aortic compliance (SV/AoPP) and the change in SV/AoPP following lower body negative pressure (LBNP) release.
Figure 4
Figure 4
The changes in normalized systolic, diastolic, and pulsatile middle cerebral arterial velocity (MCAv) after the release of LBNP up to 15 s.

Similar articles

Cited by

References

    1. Alexandrov A. V., Sloan M. A., Tegeler C. H., Newell D. N., Lumsden A., Garami Z., et al. . (2012). Practice standards for transcranial Doppler (TCD) ultrasound. Part II. Clinical indications and expected outcomes. J. Neuroimaging 22, 215–224. 10.1111/j.1552-6569.2010.00523.x - DOI - PubMed
    1. Bateman G. A. (2004). Pulse wave encephalopathy: a spectrum hypothesis incorporating Alzheimer's disease, vascular dementia and normal pressure hydrocephalus. Med. Hypotheses 62, 182–187. 10.1016/S0306-9877(03)00330-X - DOI - PubMed
    1. Bhella P. S., Hastings J. L., Fujimoto N., Shibata S., Carrick-Ranson G., Palmer M. D., et al. . (2014). Impact of lifelong exercise “dose” on left ventricular compliance and distensibility. J. Am. Coll. Cardiol. 64, 1257–1266. 10.1016/j.jacc.2014.03.062 - DOI - PMC - PubMed
    1. Caselli S., Di Pietro R., Di Paolo F. M., Pisicchio C., di Giacinto B., Guerra E., et al. . (2011). Left ventricular systolic performance is improved in elite athletes. Eur. J. Echocardiogr. 12, 514–519. 10.1093/ejechocard/jer071 - DOI - PubMed
    1. Davis S. M., Ackerman R. H., Correia J. A., Alpert N. M., Chang J., Buonanno F., et al. . (1983). Cerebral blood flow and cerebrovascular CO2 reactivity in stroke-age normal controls. Neurology 33, 391–399. 10.1212/WNL.33.4.391 - DOI - PubMed

LinkOut - more resources