Back to Publications​
Publication
Nature Medicine

Characterizing the physiology of circulatory arrest in humans

Back to Publications​
  • October 16, 2025
  • Mypinder S. Sekhon, et al., University of British Columbia
Topic/Product:
CNS Disease Panel 120, Neurology
Disease Area:
Circulatory Arrest
Sample Type:
Plasma

Abstract

The dying process from circulatory arrest is an underexplored domain in humans and has transdisciplinary pertinence. Here we conducted a prospective, observational cohort study of the dying process in 39 adults, with a multimodal assessment of cerebrovascular and cardiovascular physiology. We found that cerebral blood velocities and brain tissue oxygen tensions ceased before systemic hemodynamics. The brain exhibited diffusion limitation of oxygen extraction during the dying process compared with extracranial tissues. Anterior and posterior brain circulations had differences in timing of cessation of circulation and physiologic responses during the dying process. Blood-based neurologic biomarkers from the brain did not change during the associated ischemia related to the dying process. Heart pathology was associated with the length of the dying process. This study provides proof-of-concept of an in vivo human model to comprehensively investigate severe cerebral ischemia and the human dying process. 

Read the Publication

Authors & Affiliations

Jordan D. Bird¹, Laura Hornby¹, Veronica Hirsch-Reinshagen², Chloe P. Allen¹, George Isac¹³, Peter A. Gooderham⁴, Sam D. Shemie⁵, Sonny Dhanani⁶, Sonny Thiara¹, Sophie Stukas¹²⁷, Rebecca Grey¹, Denise A. Foster¹, Lauren E. Maier¹, Allana E. LeBlanc⁸, Hussein D. Kanji¹, Tessa F. Morelli²⁷, Andrew M. Agbay²⁷, Cheryl L. Wellington²⁷, Daljeet Chahal⁹, Eric C. Belanger², Hezhen Ren², Pushwant S. Mattu², Susan Su⁸, Chantelle T. Hrazdil¹⁰, Jennifer Percy¹⁰, Parveen Sangha⁸, Laurel V. Plewes⁸, David D. Sweet¹, Kali R. Romano¹³, Erik N. Vu¹, Dean R. Chittock¹, Vinay K. Dhingra¹, William R. Henderson¹, Naisan R. Garraway¹, S. Morad Hameed¹¹, Gordon N. Finlayson¹³, David B. MacLeod¹², Travis D. Gibbons¹³, Philip N. Ainslie¹⁴, Ryan L. Hoiland⁷¹⁵¹⁶, Donald E. Griesdale¹³¹⁷, Juan J. Ronco¹, and Mypinder S. Sekhon¹⁷

¹ Division of Critical Care Medicine, Department of Medicine, Faculty of Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
² Department of Pathology and Laboratory Medicine, Faculty of Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
³ Department of Anaesthesiology, Pharmacology and Therapeutics, Faculty of Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
⁴ Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
⁵ Division of Pediatric Critical Care, Montreal Children’s Hospital, McGill University Health Centre, Montreal, Quebec, Canada
⁶ Division of Critical Care, Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
⁷ Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
⁸ Vancouver Coastal Health, Vancouver, British Columbia, Canada
⁹ Division of Gastroenterology, Department of Medicine, Faculty of Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
¹⁰ Division of Neurology, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
¹¹ Department of Surgery, Stanford University, Stanford, CA, USA
¹² Department of Anaesthesiology, Duke University Medical Center, Durham, NC, USA
¹³ Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
¹⁴ Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia–Okanagan, Kelowna, British Columbia, Canada
¹⁵ Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
¹⁶ Centre for Chronic Disease Prevention and Management, Faculty of Medicine, University of British Columbia, Kelowna, British Columbia, Canada
¹⁷ International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada

Linkedin

Steve Williams, MD, PhD

CSO

Dr. Willams serves as the company’s Chief Scientific Officer. He was previously Chief Medical Officer at Standard Biotools and at SomaLogic where he pioneered the discipline for discovery and validation of predictive, diagnostic and prognostic models using machine-learning applied to large-plex proteomics. 20 such tests were used for drug characterization, safety and efficacy when incorporated in clinical drug trials at Pharma/Biotech and 17 different multivariate tests were validated and translated into regulated healthcare uses. Prior to SomaLogic, Dr. Williams was at Pfizer in the UK and the USA as a clinical triallist in Translational Medicine, and subsequently as VP, Global Clinical Technology. He sat on the National Advisory Council for the National Institute of Biomedical Imaging and Bioengineering, the Executive Committee for the FNIH Biomarkers Consortium, and worked with FDA and PhRMA on developing evidentiary standards for biomarker qualification. Dr. William’s medical training was in London, at Charing Cross and Westminster Medical School, followed by a PhD in medicine/physiology at the same institution and training in Radiology at the University of Newcastle Upon Tyne. Steve is co-inventor on 26 proteomics patents and author/coauthor on multiple foundational proteomics manuscripts.

Linkedin

Justin McAnear

CFO

Mr. McAnear serves as the company’s Chief Financial Officer. He brings over 25 years of operational and financial leadership experience across various sectors and was instrumental in taking 10x Genomics public in 2019, serving as its CFO for over five years. Mr. McAnear served for over 3 years as Tesla’s VP of Worldwide Finance and Operations, supporting landmark initiatives such as the Model X and Model 3 launches and Solar City acquisition.  He also held various roles at Apple and J&J earlier in his career and served as a naval officer and aviator for over 9 years.