Understanding how heart rate affects blood flow in the brain

Assessment of the Relationship Between Cerebral Blood Flow and Heart Rate: An Electrophysiology Based Study

Not applicable Interventional University of Calgary · NCT04391465

This study is testing how changes in heart rate affect blood flow to the brain in patients with postural tachycardia syndrome to help improve their symptoms and quality of life.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment20 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorUniversity of Calgary Academic / other
Locations1 site (Calgary, Alberta)
Trial IDNCT04391465 on ClinicalTrials.gov

What this trial studies

This study aims to explore the relationship between heart rate and cerebral blood flow (CBF) in the middle cerebral artery (MCA) by utilizing temporary pacing catheters in patients undergoing elective electrophysiological procedures. Researchers will measure MCA CBF using transcranial Doppler ultrasound while manipulating heart rate to assess its impact on CBF. The study focuses particularly on patients with postural tachycardia syndrome (POTS), who often experience chronic orthostatic symptoms and reduced cardiac output. By investigating this relationship, the study seeks to enhance understanding of the hemodynamic determinants of CBF and potentially improve quality of life for affected patients.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18-70 who are scheduled for elective electrophysiological studies and have a left ventricular ejection fraction of 50% or greater.

Not a fit: Patients who are unable or unwilling to provide informed consent or have other conditions preventing protocol completion may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to better management strategies for patients with POTS and improve their quality of life.

How similar studies have performed: While the relationship between heart rate and CBF has not been extensively studied in POTS patients, previous research has shown that increased cardiac output can improve CBF, indicating potential for success in this novel approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Male or female
* Age 18-70 years, inclusive
* Scheduled for clinically indicated elective electrophysiological studies where temporary pacing catheters are being placed in the right atrium
* Left ventricular ejection fraction ≥50%
* Able and willing to provide informed consent
* Able to travel to the Cardiac Electrophysiology Laboratory at the Foothills Medical Centre, Calgary, Alberta, Canada

Exclusion Criteria:

* Unable or unwilling to provide informed consent
* Other factors which in the investigator's opinion would prevent the participant from completing the protocol

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 Cerebrovascular CirculationPhysiologyCerebral Blood Flow
Last reviewed 2026-06-15 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.