Actively Recruiting
Assessment of the Relationship Between Cerebral Blood Flow and Heart Rate: An Electrophysiology Based Study
Led by University of Calgary · Updated on 2026-05-07
20
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are studying the relationship between heart rate and blood flow in the middle cerebral artery (MCA), aiming to better understand how heart rate affects cerebral blood flow velocity. This is particularly relevant for conditions like postural tachycardia syndrome (POTS), where patients experience chronic symptoms such as dizziness and fainting due to possible changes in cerebral blood flow. The study focuses on the hemodynamic factors influencing MCA blood flow using patients already scheduled for elective electrophysiological studies. The study involves temporarily pacing the heart at controlled rates using a catheter placed in the right atrium during an electrophysiology procedure. Participants will undergo pacing at four different heart rates—100, 120, 150, and 171 beats per minute—for one minute each, with rest periods in between. Heart rate, blood pressure, and MCA cerebral blood flow velocity will be continuously monitored using skin electrodes, finger cuffs, and transcranial Doppler ultrasound. Data on stroke volume, cardiac output, and vascular resistance will be collected to analyze their relationship with cerebral blood flow. Participants will be monitored while lying down during the procedure, which adds about 10 to 15 minutes to their planned electrophysiology study. Assessments include continuous heart rate and blood pressure monitoring, Doppler ultrasound to measure blood flow velocity, and recording of cardiac function parameters. The main measurement is the change in MCA cerebral blood flow velocity in response to pacing at 150 beats per minute compared to baseline. Safety and hemodynamic responses will be observed during and after pacing, with the clinical procedure continuing as planned afterward.
CONDITIONS
Brief Title
Assessment of the Relationship Between Cerebral Blood Flow and Heart Rate
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Male or female
- Age 18-70 years, inclusive
- Scheduled for clinically indicated elective electrophysiological studies with temporary pacing catheters placed in the right atrium
- Left ventricular ejection fraction of 50% or higher
- Able and willing to provide informed consent
- Able to travel to the Cardiac Electrophysiology Laboratory at the Foothills Medical Centre, Calgary, Alberta, Canada
You will not qualify if you...
- Unable or unwilling to provide informed consent
- Other factors which in the investigator's opinion would prevent the participant from completing the protocol
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Approximately 10 to 15 minutes during a scheduled electrophysiology procedure
Participants undergo electrophysiological pacing with high right atrial pacing at several heart rates while supine. Heart rate will be paced at 100, 120, 150, and 171 beats per minute, each for 60 seconds with rest periods in between, to assess cerebral blood flow velocity and hemodynamic responses.
1 in-person visit during electrophysiology study
Trial Site Locations
Total: 1 location
1
Foothills Medical Center
Calgary, Alberta, Canada, T2N 4Z6
Actively Recruiting
Research Team
S
Satish R Raj, MD MSCI
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
SINGLE_GROUP
Primary Purpose
TREATMENT
Number of Arms
1
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