Heart Rate Variability As A Measure Of Cardiovascular Health In Individuals With Spinal Cord Injury

Abstract

The purpose of this study is to examine the acute responses to exercise alone, heat therapy alone, and both exercise and heat therapy on leg blood flow, blood pressure, and heart rate variability in patients who have an injury below T6 thoracic vertebrae. Due to their inability to perform full-body exercises, they tend to have lower heart rate variability and a higher chance of cardiovascular disease. Briefly, medically stable men and women with spinal cord injury (SCI) will be recruited to take part in 3 trials consisting of matched exercise (Heart rate monitored during 20 minutes of rowing) with a post-exercise treatment of 45 minutes of hot (42C) leg bathing, matched exercise (Heart rate monitored during 20 minutes of rowing) with a post-exercise treatment of 45 minutes of thermoneutral (36C) leg bathing, and no exercise with a post-exercise treatment of 45 minutes of hot (42C) leg bathing. HRV will be tracked for 24 hours pre-trial, 12 hours post-trial, and overnight (rMSSD). Leg blood flow and finometer will be measured pre-trial and during 45 minutes into leg bath. Tympanic temp, HR, and brachial BP will be measured pre-trial and 5 minutes during leg bath. We hypothesize that post-exercise leg immersion in a hot bath will increase lower leg blood flow and overnight heart rate variability to a greater extent than either exercise alone or leg heating alone. This study highlights the importance of tracking the heart rate variability while finding alternatives (exercise; heat therapy) for patients with SCI because it serves as a critical pointer for any cardiovascular risk. This study will help the people with SCI and be used as a base study for future researchers.