Comparison between invasive and non-invasive measures of sympathetic nerve activity during autonomic function tests in adults


To study, evaluate, and compare invasive and non-invasive sympathetic nerve activity (fight or flight response) measurements during tests of breathing, a handgrip test (pushing against force), and a cold pressor test (hand in ice water)


Currently recruiting participants: Yes

Eligible ages: 18 to 85

Accepts healthy participants: Yes

Inclusion criteria:

1. Patients with a disorder of orthostatic tolerance
2. No known disorder of orthostatic tolerance (healthy controls)
4. Age between 18-85 years
5. Male and female participants are eligible
6. Able and willing to provide informed consent

Exclusion criteria:

1. Unable to give informed consent
2. An inability to safely withdraw from medicine(s) that could make test interpretation difficult or impossible
3. Other factors which in the investigator’s opinion would prevent the participant from completing the protocol, including poor compliance during previous studies or an unpredictable schedule


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Method of contact

Additional information

Contact information

Jiyao Qi (Research Assistant): 403-210-7627

Principal investigator:

Satish Raj

Clinical trial: