Premium
A novel non‐invasive method to measure sympathetic activity and autoregulation in humans
Author(s) -
Wilson Richard JA.,
Jendzjowsky Nicholas,
Steinback Craig,
Tsai Willis H.,
Herman Robert J.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.920.4
Subject(s) - microneurography , heart rate variability , autoregulation , heart rate , medicine , sympathetic nervous system , baroreflex , hyperventilation , cardiology , blood pressure , autonomic nervous system , hypoxia (environmental) , chemistry , organic chemistry , oxygen
Current methods to assess sympathetic nervous system activity are associated with technical difficulty, invasiveness (microneurography) and poor temporal resolution ([plasma norepinephrine]). Use of heart rate variability overcomes most of these issues but is controversial because of limited accuracy. We have developed a quick, easy and non‐invasive approach based on spectral domain optical coherence tomography (OCT) that also allows investigation of arterial autoregulation. Here, we compare OCT and heart rate variability to microneurography, the gold standard of sympathetic assessment. We recruited 6 healthy males (26±3y) and 5 healthy females (23±1y), instrumented them for ECG and muscle sympathetic nerve microneurography and exposed them to respiratory and sympathetic provocations. Choroid vascular perfusion density (VPD) decreases with cold pressor test, inhaled hypoxia and breath‐hold, and increases with hyperoxia and hyperventilation suggesting that sympathetic activity dominates choroid responses. In contrast, retinal pigment epithelium VPD was unaffected by the cold pressor test, increased with hypoxia and breath hold and decreases with hyperoxia and hyperventilation, suggesting autoregulation dominates the retinal pigment epithelium. With regards to integrated muscle sympathetic nerve activity, heart rate variability had low predictive power whereas OCT was strongly (inversely) correlated (R= −0.91; p<0.01). These data suggest OCT may provide a novel approach to assessing autoregulation and sympathetic activity with superior predictability compared to heart rate variability. Given that sympathetic nervous system activity is a main determinant of autonomic function, sympathetic excitation is associated with serious cardiorespiratory/metabolic diseases and autoregulation is critical for brain health, we suggest that this new OCT technique will be of broad use to clinicians and researchers alike. Support or Funding Information This study was supported by Canadian Institute for Health Research (RJAW & WT). RJAW is an Alberta Innovates Health Solutions Senior Scholar. NGJ received postdoctoral salary support for this project from Alberta Innovates Health Solutions and the T Chen Fong Foundation. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .