Effects of CO2 on heart rate and symptoms in POTS patients

Hypercapnia and Orthostatic Tolerance in Postural Orthostatic Tachycardia Syndrome

Not applicable Interventional University of Calgary · NCT04271878

This study tests if breathing in higher levels of carbon dioxide can help improve heart rate and symptoms for people with Postural Orthostatic Tachycardia Syndrome (POTS).

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment26 (estimated)
Ages18 Years to 60 Years
SexAll
SponsorUniversity of Calgary Academic / other
Locations1 site (Calgary, Alberta)
Trial IDNCT04271878 on ClinicalTrials.gov

What this trial studies

This research investigates the impact of increased carbon dioxide levels on heart rate and symptoms in patients with Postural Orthostatic Tachycardia Syndrome (POTS). The study utilizes the RespirAct™ system to control and monitor gas concentrations during inhalation, aiming to determine the optimal CO2 levels that may alleviate orthostatic symptoms. By examining the relationship between hypercapnia and orthostatic tolerance, the researchers hope to provide a new therapeutic approach for managing POTS. The study will include participants aged 18-60 diagnosed with POTS who can travel to the University of Calgary for testing.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18-60 with a physician diagnosis of Postural Tachycardia Syndrome.

Not a fit: Patients with acute dehydration, severe anxiety, chronic heart failure, or those unable to tolerate the study protocol may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could offer a novel treatment option for patients suffering from POTS by reducing heart rate and improving symptoms.

How similar studies have performed: While previous studies have shown some effects of CO2 on heart rate in small groups, this approach is still relatively novel for the broader POTS population.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Physician diagnosis of Postural Tachycardia Syndrome (POTS)
* Age 18-60 years
* Male and Female
* Non - smokers.
* Able and willing to provide informed consent.
* Ability to travel to Libin Cardiovascular Institute of Alberta Autonomic Testing Lab at the University of Calgary, Calgary, AB.

Exclusion Criteria:

* Overt cause for postural tachycardia, i.e., acute dehydration
* Participants with somatization or severe anxiety symptoms will be excluded
* Pregnant
* Inability to tolerate mask for the duration of the study
* Subjects who require portable oxygen at rest or with exercise
* Subjects with chronic heart failure or severe pulmonary disease who are unable to climb one flight of stairs due to shortness of breath.
* Other factors which in the investigator's opinion would prevent the participant from completing the protocol, including poor compliance during previous studies.

Where this trial is running

Calgary, Alberta

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Postural Tachycardia SyndromeOrthostatic Intolerancepostural tachycardiaautonomicorthostatic intolerancedysautonomia
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.