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Squair JW, Lee AH, Sarafis ZK, Chan F, Barak OF, Dujic Z, Day T, Phillips AA. Network analysis identifies consensus physiological measures of neurovascular coupling in humans. J Cereb Blood Flow Metab 2020; 40:656-666. [PMID: 30841780 PMCID: PMC7026847 DOI: 10.1177/0271678x19831825] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Intimate communication between neural and vascular structures is required to match neuronal metabolism to blood flow, a process termed neurovascular coupling. The number of laboratories assessing neurovascular coupling in humans is increasing due to clinical interest in disease states, and basic science interest in a non-anesthetized, non-craniotomized, unrestrained, in vivo model. However, there is a lack of knowledge regarding how best to characterize the neurovascular response. To address this knowledge gap, we have amassed a highly powered human neurovascular coupling dataset, and deployed a network-based approach to reveal the most powerful and consistent metrics for quantifying neurovascular coupling. Using dimensionality reduction, community-based clustering, and majority-voting of traditional metrics (e.g. peak response, time to peak) and non-traditional metrics (e.g. varying time windows, pulsatility), we have identified which of the existing metrics predominantly characterize the neurovascular coupling response, are stable within and across participants, and explain the vast majority of the variance within our dataset of over 300 trials. We then harnessed our empirical approach to generate powerful novel metrics of neurovascular coupling, termed iAmplitude, iRate, and iPulsatility, which increase sensitivity when capturing population differences. These metrics may be useful to optimally understand neurovascular coupling in health and disease.
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Affiliation(s)
- Jordan W Squair
- Departments of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Canada.,International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,MD/PhD Training Program, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Department of Experimental Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Amanda Hx Lee
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Department of Experimental Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Zoe K Sarafis
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Franco Chan
- Departments of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Otto F Barak
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Zeljko Dujic
- ▪, University of Split School of Medicine, Split, Croatia
| | - Trevor Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Canada
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Canada
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Duschek S, Hoffmann A, Montoro CI, Reyes del Paso GA. Autonomic Cardiovascular Dysregulation at Rest and During Stress in Chronically Low Blood Pressure. J PSYCHOPHYSIOL 2019. [DOI: 10.1027/0269-8803/a000204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Abstract. Chronic low blood pressure (hypotension) is accompanied by symptoms such as fatigue, reduced drive, faintness, dizziness, cold limbs, and concentration difficulties. The study explored the involvement of aberrances in autonomic cardiovascular control in the origin of this condition. In 40 hypotensive and 40 normotensive subjects, impedance cardiography, electrocardiography, and continuous blood pressure recordings were performed at rest and during stress induced by mental calculation. Parameters of cardiac sympathetic control (i.e., stroke volume, cardiac output, pre-ejection period, total peripheral resistance), parasympathetic control (i.e., heart rate variability), and baroreflex function (i.e., baroreflex sensitivity) were obtained. The hypotensive group exhibited markedly lower stroke volume, heart rate, and cardiac output, as well as higher pre-ejection period and baroreflex sensitivity than the control group. Hypotension was furthermore associated with a smaller blood pressure response during stress. No group differences arose in total peripheral resistance and heart rate variability. While reduced beta-adrenergic myocardial drive seems to constitute the principal feature of the autonomic impairment that characterizes chronic hypotension, baroreflex-related mechanisms may also contribute to this state. Insufficient organ perfusion due to reduced cardiac output and deficient cardiovascular adjustment to situational requirements may be involved in the manifestation of bodily and mental symptoms.
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Affiliation(s)
- Stefan Duschek
- UMIT – University of Health Sciences Medical informatics and Technology, Institute of Psychology, Hall in Tirol, Austria
| | - Alexandra Hoffmann
- UMIT – University of Health Sciences Medical informatics and Technology, Institute of Psychology, Hall in Tirol, Austria
| | - Casandra I. Montoro
- UMIT – University of Health Sciences Medical informatics and Technology, Institute of Psychology, Hall in Tirol, Austria
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Duschek S, Hoffmann A, Reyes Del Paso GA. Affective impairment in chronic low blood pressure. J Psychosom Res 2017; 93:33-40. [PMID: 28107890 DOI: 10.1016/j.jpsychores.2016.12.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/21/2016] [Accepted: 12/10/2016] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Physical complaints such as faintness, dizziness, cold limbs and headaches have been well-established in chronic low blood pressure (hypotension). This study investigated the occurrence of adverse emotional states and the symptoms of depression in this condition. As autonomic dysregulation, particularly diminished sympathetic tone, is believed to be involved in the etiology of hypotension, the impact of different facets of autonomic cardiovascular control on mood and depressive symptoms was also explored. METHODS Forty individuals with chronic hypotension and forty normotensive control persons were presented with the Mood Scale and Beck Depression Inventory. Stroke volume, cardiac output, pre-ejection period, Heather index and aortic peak blood flow velocity were recorded under resting conditions as indices of beta-adrenergic inotropic drive. Respiratory sinus arrhythmia and baroreflex sensitivity were additionally obtained. RESULTS Hypotensive individuals scored markedly higher on both questionnaire scales than controls, indicating an adversely affected emotional state and more severe depressive symptoms. In the entire sample, cardiac output, Heather index, and aortic peak blood flow velocity correlated negatively with the questionnaire scores; according to regression analysis, the Heather index explained the largest proportion of test score variance. CONCLUSION Although hypotension does not constitute a serious medical condition, the findings of an adverse affective state and increased burden with depressive symptoms corroborate the view that it can have a considerable impact on wellbeing and quality of life. The correlations of the beta-adrenergic indices with the questionnaire scales indicate that cardiac sympathetic regulation plays a key role in the psychophysiological mediation of hypotension-related mood impairment.
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Affiliation(s)
- Stefan Duschek
- UMIT - University of Health Sciences Medical Informatics and Technology, Institute of Psychology, Austria.
| | - Alexandra Hoffmann
- UMIT - University of Health Sciences Medical Informatics and Technology, Institute of Psychology, Austria
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