Heart rate changes associated with autonomic dysreflexia in daily life of individuals with chronic spinal cord injury

Belinda Yee, Tom E. Nightingale, Andrea L. Ramirez, Matthias Walter, Andrei Krassioukov

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Study design: Secondary data analysis.

Objective: To characterize heart rate (HR) changes during autonomic dysreflexia (AD) in daily life for individuals with chronic spinal cord injury (SCI).

Setting: University-based laboratory/community-based outpatient.

Methods: Cardiovascular data, previously collected during a 24-h ambulatory surveillance period in individuals with chronic SCI, were assessed. Any systolic blood pressure (SBP) increase ≥20 mmHg from baseline was identified and categorized into confirmed AD (i.e., diarized trigger), unknown (i.e., no diary entry), or unlikely AD (i.e., potential exertion driven SBP increase) groups. SBP-associated HR changes were categorized as unchanged, increased or decreased compared to baseline.

Results: Forty-five individuals [8 females, median age and time since injury of 43 years (lower and upper quartiles 36–50) and 17 years (6–23), respectively], were included for analysis. Overall, 797 episodes of SBP increase above AD threshold were identified and classified as confirmed (n = 250, 31.4%), unknown (n = 472, 59.2%) or unlikely (n = 75, 9.4%). The median number of episodes per individual within the 24-h period was 13 (8–28). HR-decrease/increase ratio was 3:1 for confirmed and unknown, and 1.5:1 for unlikely episodes. HR changes resulting in brady-/tachycardia were 34.4%/2.8% for confirmed, 39.6%/3.4% unknown, and 26.7%/9.3% for unlikely episodes, respectively.

Conclusions: Our findings suggest that the majority of confirmed AD episodes are associated with a HR decrease. Using wearable-sensors-derived measures of physical activity in future studies could provide a more detailed characterization of HR changes during AD and improve AD identification.
Original languageEnglish
JournalSpinal Cord
Early online date9 Jun 2022
Publication statusE-pub ahead of print - 9 Jun 2022

Bibliographical note

Funding Information:
BY is a University of British Columbia—Faculty of Medicine Summer Student Research Program (FoM SSRP) award recipient. TEN (grant number 17767) and MW (grant number 17110) were recipients of Michael Smith Foundation for Health Research Trainee Awards in conjunction with the International Collaboration on Repair Discoveries and Rick Hansen Foundation, respectively. AVK is supported by Endowed Chair, Department of Medicine, Univerty of British Columbia. Funding was provided for NCT02298660 (by Praxis Spinal Cord Institute, i.e., formerly Rick Hansen Institute, grant number G2013-09 and Allergan Inc.), NCT02676154 (by Pfizer Canada investigator-initiated research, grant number WI207218), and cross-sectional study (by Praxis Spinal Cord Institute, grant number G2015-31).

Publisher Copyright:
© 2022, The Author(s), under exclusive licence to International Spinal Cord Society.


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