UBC Faculty Research and Publications

Orthostatic hypotension among elite wheelchair athletes Mikhail, David 2010

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PI: Andrei V. Krassioukov, MD, PhD, FRCPC David Mikhail*, P. Mills, F. Biering-Sørensen, D. Campbell, J. Eng, R. O’Connor, J. Taunton,  A. Tawashy, D. Warburton, and A. Krassioukov ICORD, Department of Medicine, University of British Columbia and University of Western Ontario, Canada UBC, B.Sc. Integrated Sciences (2009) UWO, 1st year medical student (2013) Objectives: 1) Outline current paralympic classification of wheelchair rugby athletes 2) Present cardiovascular responses in wheelchair rugby athletes 3) Outline future directions for the integration of autonomic assessments into paralympic athlete classification Athletic Training/Performance Q1. What does our body do when we start to exercise?  Increased heart rate  Increased blood pressure  Increased peripheral blood flow (musculature!)  Increased respiration These changes occur to fuel our body to keep up with the high physical demands of exercise! Athletic Training/Performance Q2. What is different for people with SCI?  Resting BP is usually low  Persistent orthostatic hypotension  Post-exercise induced hypotension  Poor response in heart rate  Episodes of uncontrolled autonomic dysreflexia These result in decreased athletic performance and could encourage some unusual techniques used by wheel chair athletes (i.e. Boosting) to compensate for the abnormal cardiovascular control! The Paralympic Games Winter Games  Wheelchair Rugby  Wheelchair Basketball  Alpine Skiing  Biathlon Summer Games  Wheelchair Fencing  Wheelchair Tennis  Boccia  Football  Goalball  Archery  Cycling  Equestrian  Volleyball  Cross-Country Skiing  Sledge Hockey  Curling •Judo •Powerlifting •Rowing •Sailing •Shooting •Swimming •Table tennis Wheelchair Rugby Classification o Bench Test  (ball handling ability) oFunctional Trunk Test (trunk stability) oFunctional Movement Tests (maneuvering ability) oOn-Court Evaluation Rugby Classes Profile: •1st class – 0.5 •2nd class – 1.0 •3rd class – 1.5 •4th class – 2.0 •5th class – 2.5 •6th class – 3.0 •7th class – 3.5 Total players on the court: 4 Total score allowed: 8.0 The Paralympics  What do we know about SCI patients?  Episodes of autonomic dysreflexia  Resting hypotension  Orthostatic hypotension  Post-prandial hypotension  Post-exercise induced hypotension  Arrythmias  Poor heart rate response during exercise (Clayden, Hall, Eng, Krassioukov, 2005) Current classification of wheelchair athletes does not take into account autonomic functions - placing some athletes at a distinct advantage or disadvantage in comparison to others, especially those with SCI. Study Objectives and Design:  Objective: To develop a validated system for functional autonomic assessment of wheelchair Paralympic athletes  In consideration of “fair play” and safety.  Research Design: prospective, cross-sectional study  Research participants:  male and female wheelchair athletes,  Ages 18-45 Subjects:  Paralympians from five international rugby teams  Total number: 25 male  Cervical/Thoracic: 22/3  C5 2  C6 10  C7 9  C8 1  T1-5 3  Average time post SCI:13±5 years  Average age: 32±5 years  Classifications  0.5-1.5 9 players (36%)  2-2.5 12 players (48%)  3-3.5 4 players (16%) Orthostatic Sit-Up Test Protocol of Study – 1. 10 minutes rest 2. Orthostatic challenge test Parameters Recorded– 1. Resting SBP/DBP and HR 2. BP and HR responses to orthostatic challenge 3. Sympathetic Skin Responses 4. Symptoms during orthostatic test Changes in blood pressure following sit up test in individuals with cervical complete (n=10) and incomplete (n=12) SCI Average classification = 1.80 Average classification = 1.88 104 mmHg 102 mmHg *Orthostatic hypotension was observed in ~43% of subjects *Many developed dizziness and lightheadedness! Most common symptoms during sit-up test COMPLETE INCOMPLETE  Light-headedness (10%)  Dizziness (20%)  Test-stopped or interrupted  Light-headedness (8%)  Dizziness (25%)  Test stopped or interrupted (0%)  Syncope (0%) (0%)  Syncope (0%) *Overall, 43% of these elite wheelchair athletes developed orthostatic hypotension Conclusions:  It was documented previously that cardiovascular dysfunctions including orthostatic hypotension are common among individuals with SCI  We are presenting novel information that up to 43% of elite Paralympic athletes experience symptomatic orthostatic hypotension during international competition.  Together with the International Paralympic Committee (IPC), we propose the need for the addition of autonomic evaluations into future Paralympic classification. Acknowledgment:  PI: Dr. A. Krassioukov Div. PM&R, Dep. Medicine, UBC; krassioiukov@icord.org  Co-investigators:  Dr. Russell O’Connor Div. PM&R, Dep. Medicine, UBC; Russell.OConnor@vch.ca  Dr. Patricia Mills Div. PM&R, Dep. Medicine, UBC; Patricia.Mills@vch.ca  Dr. Darren Warburton Experimental Medicine Program, UBC; darrenwb@interchange.ubc.ca  Dr. Jack Taunton Division of Sports Medicine, UBC;  jack.taunton@ubc.ca  Dr. Janice Eng ICORD, School of Rehab, UBC;  Janice.Eng@vch.ca  Dr. Fin Biering-Sørensen Spinal Unit, Copenhagen, DK;  fin.biering-soerensen@rh.regionh.dk  Mrs. Shirley Wong Grad Student, ICORD/UBC, scwong.ubc@gmail.com  Mrs. Amira Tawashy Grad Student, School of Rehab, UBC; amiratawashy@hotmail.com  Mr. David Mikhail UBC Student, ICORD/UBC; dmikhail@interchange.ubc.ca  Consultants: Wheelchair athletes & Paralympians:  Ms. Jennifer Krempien Dep. of Nutrition, UBC; jkrempien@cw.bc.ca  Dr. Jaimie Borisoff ICORD, Neil Squire Society; borisoff@gmail.com  Mr. Richard Peter BC Wheelchair Sports; richard@bcwheelchairsports.com  Mr. Duncan Campbell BC Wheelchair Sport; dunkster1@yahoo.com Supported by: Orthostatic Hypotension Among Elite Wheelchair Athletes by David Mikhail, B.Sc. and Dr. Andrei Krassioukov  SLIDES CAPTION 1 Before we begin, I would like to formally define our topic for those who are unaware – “Orthostatic Hypotension” is a form of hypotension (low blood pressure) which involves a drop of 20 mmHg systolic and/or 10 mmHg diastolic blood pressure after a change from a supine position to an upright position. 2 This presentation has three objectives which are written here. 3 Q: What do you do to prepare your body to exercise? A: NOTHING! Your sympathetic nervous system does it all for you! It controls your increase in heart rate, blood pressure, peripheral blood flow and respiration so as to fuel your body and muscles with what they need to perform.  But what happens when you DON’T have a fully- functioning sympathetic nervous system? 4 For people with spinal cord injury (SCI), this is unfortunately a reality! They have been found to have all of the cardiovascular problems listed here and more. As you can imagine, if you can’t get your heart and cardiovascular system pumping enough blood in your body, this can have a huge effect on your athletic performance and endurance – a daunting reality for a paralympic athlete. This can encourage athletes to use what is called “boosting”, which is basically when they induce tachycardia and autonomic dysreflexia in themselves by various methods, often endangering their health to improve their performance. Autonomic Dysreflexia = period of very high BP which can have mild symptoms such as sweating and headaches, but could lead to severe problems such as cerebral hemmhoraging and seizures! 5 This is just a list of the Paralympic games (summer and winter sports). 6 This slide gives us an idea of how Paralympic athletes are currently classified. For this first part of the study we looked at wheelchair rugby players. Currently, they are put through four tests: 1) Bench Test – tests their ball-handling ability 2) Functional Trunk Test – tests their trunk stability in their chair 3) Functional Movement Test – tests their overall maneuver abilities with their chair 4) On-Court Evaluation – tests their overall ability to play the game They are classified into one of 7 classes (above): 0.5 = has poor motor hand-ball control and difficulties with trunk stability and ability to move with the wheelchair 3.5 = has full motor capacity to control the ball and full stability in the wheelchair because of trunk strength NOTES: *The significance of these scores is that any team can have a TOTAL SCORE of 8.0 on the court at any time between the four players on the court* *If you haven’t noticed, this whole classification system is based completely on MOTOR function of the athletes and does not look at their autonomic nervous system function at all (which we have established controls the cardiovascular response during exercise)* 7 Above is a list of cardiovascular problems which are seen with SCI patients because of decreased cardiovascular function. Once again, I want to emphasize that the current classification (last slide) does NOT include autonomic function, which puts certain athletes (especially those with SCI) at a distinct advantage or disadvantage compared to others since this affects their ability to participate, their endurance and their performance level. Note: We are specifically talking about those with SCI and not other types of wheelchair athletes (i.e. amputees or those with spina bifida). 8 Basically, our study is aimed at developing a validated system for functional autonomic assessment and how to incorporate this into Paralympic classification by better understanding how autonomic function varies by injury and across various sports. 9 This is a breakdown of our wheelchair rugby participants. Note that most of the athletes had a cervical SCI and had a reasonably high classification. 10 The subjects were given an “orthostatic sit-up test”. Basically, we take a continuous ECG (ecocardiogram) and finometer blood pressure reading while the athlete is lying down at rest for 10 minutes, and then we sit him up in the chair (without the use of their own muscles). The athlete was also given a sympathetic skin response test, given a questionnaire about their symptoms and asked about symptoms during the tests. Here we are presenting data on the cardiovascular parameters. Note: The standard test to evaluate autonomic dysfunctions is usually the “Tilt Test”, but we did NOT use that test because the athletes compete in a seated position and we wanted to test them under the same position. The orthostatic sit-up test was validated in our laboratory in previous studies. 11 This slide summarizes the results of our study! When we analyzed the data, we found a significant difference in cardiovascular responses between athletes with cervical complete injuries (n=10) and cervical incomplete injuries (n=12). Here we are looking at the average systolic and diastolic blood pressures of the athletes. COMPLETE CERVICAL (left) – on average, we see a significant drop in systolic blood pressure indicative of orthostatic hypotension upon sit-up. INCOMPLETE CERVICAL (right) – on average, there is only a slight drop in systolic blood pressure, but not significant enough for orthostatic hypotension. Here we want to point out that the average classifications of both of these groups are almost identical (1.80 and 1.88 respectively), but the cardiovascular response is significantly different in both of these groups. This reinforces the fact that the fact that the current classification system does not sufficiently account for differences in autonomic function and cardiovascular dysfunction and that it varies among athletes! *overall, we observed symptoms of orthostatic hypotension in about 43% of the subjects, and many developed dizziness and lightheadedness upon set-up* 12 This shows that the two groups did not show a significant difference in the frequency of different symptoms which presented during the test. 13 To summarize our conclusions and directions: We found that there is a need for autonomic function to be included in paralympic athlete classification to maintain fairness in competition and decrease pressure on athletes to use “boosting” techniques. By including autonomic function in classification, we can increase or decrease individual’s scores and allow for more fair gameplay. We hope to do more studies with more sports in the future (including these winter Paralympics in Vancouver, and wheelchair basketball players in the future) to better understand the best way to add to the classification system. 14 Thank you for reading! I would like to thank the IPC (International Paralympic Committee) and DHRN (Disabilities Health Research Network) for support and funding of this project! As well, everyone involved and Dr. Andrei Krassioukov. 


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