Heart Rate Control for Cerebrovascular Physiology

Overseen By Satish R Raj, MD MSCI

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Calgary

Disqualifiers: Informed consent, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 1

20 Participants Needed

Trial Summary

What is the purpose of this trial?

The investigators will seek to determine the relationship between heart rate and middle cerebral artery (MCA) cerebral blood flow (CBF), as well as better understand the hemodynamic determinants of MCA CBF velocity. In order to manipulate heart rate, the investigators will recruit patients already scheduled for clinically indicated elective electrophysiological studies, where temporary pacing catheters placed in the right atrium can be used to artificially pace the heart at controlled rates. MCA CBF will be measured by transcranial Doppler ultrasound.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. Please consult with the trial coordinators for more details.

What data supports the effectiveness of the treatment Electrophysiological Pacing, Electrophysiological Pacing, Cardiac Pacing, Temporary Pacing for Heart Rate Control for Cerebrovascular Physiology?

Temporary cardiac pacing is effective for treating various heart rhythm issues, and rate-responsive pacing can improve exercise ability in patients with certain heart conditions by adjusting the heart rate based on the body's needs. This suggests that pacing can help manage heart rate effectively, which may support its use in controlling heart rate for cerebrovascular health. ^{1 2 3 4 5}

Is cardiac pacing generally safe for humans?

Cardiac pacing, including temporary and noninvasive methods, is generally considered safe for humans. Some studies have shown it to be effective with minor discomfort as a side effect, especially in conscious patients. However, certain methods may cause discomfort or require skill and experience to perform safely. ^{3 6 7 8 9}

How is Electrophysiological Pacing different from other treatments for cerebrovascular physiology?

Electrophysiological Pacing is unique because it uses electrical impulses to control heart rate, which can help manage both slow and fast heart rhythms when other treatments fail. Unlike medications, this treatment directly influences the heart's electrical system to stabilize heart rhythms, making it a valuable option for acute arrhythmias. ^{3 4 9 10 11}

Research Team

Satish R Raj, MD MSCI

Principal Investigator

University of Calgary

Eligibility Criteria

This trial is for adults aged 18-70 with a healthy heart pump function, scheduled for elective heart rhythm studies where they'll get temporary pacing wires in the right atrium. Participants must consent to the study and be able to visit the Cardiac Electrophysiology Lab in Calgary, Canada.

Inclusion Criteria

I am scheduled for a heart rhythm test that involves placing pacing wires in the right side of my heart.

Able and willing to provide informed consent

I am between 18 and 70 years old.

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

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Electrophysiological Study

Participants undergo high right atrial pacing at various rates to assess the relationship between heart rate and cerebral blood flow

10-15 minutes

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the electrophysiological study

4 weeks

Treatment Details

Interventions

• Electrophysiological Pacing

Trial Overview The study aims to understand how different heart rates affect blood flow in a brain artery by using controlled electrical stimulation of the heart during routine electrophysiological procedures and measuring blood flow with an ultrasound on the head.

Participant Groups

Group I: Patients Scheduled for Elective Electrophysiological Study Experimental Treatment 1 Intervention

High right atrial pacing will occur at the following rates for 60 seconds each, with a rest period of at least 60 seconds between pacing runs: * 600 msec (100 bpm) * 500 msec (120 bpm) * 400 msec (150 bpm) * 350 msec (171 bpm)

Electrophysiological Pacing is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Electrophysiological Pacing for:

• Arrhythmias
• Heart failure
• Cardiac arrest prevention

Approved in European Union as Electrophysiological Pacing for:

• Arrhythmias
• Heart failure
• Cardiac arrest prevention
• Bradycardia

Approved in Canada as Electrophysiological Pacing for:

• Arrhythmias
• Heart failure
• Cardiac arrest prevention

Who Is Running the Clinical Trial?

University of Calgary

Lead Sponsor

Trials

827

Recruited

902,000+

Findings from Research

In a study of 152 patients undergoing pacemaker implantation, those with symptoms of cerebral hypoperfusion had a higher prevalence of significant stenosis in carotid arteries compared to asymptomatic patients (32% vs. 16%).

Patients with a second degree atrioventricular block and no atherosclerotic lesions had the lowest risk of experiencing symptoms like syncope, suggesting that ultrasonographic evaluation of carotid and vertebral arteries could be crucial for symptomatic patients before pacemaker surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Flow disturbances in carotid and vertebral arteries in symptomatic patients referred for pacemaker implantation. Dabrowski, R., Maciag, A., Kowalik, I., et al.[2016]

Electronic pacing is an effective treatment for patients experiencing slow ventricular heart rates, providing options for both temporary and permanent solutions.

The choice of pacing mode (epicardial vs. endocardial, fixed vs. demand) is tailored to the individual patient's clinical condition and response to treatment, ensuring optimal care.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Recent advances in artificial pacemakers. Bilitch, M., Lau, FK., Cosby, RS.[2018]

Ultrasound-guided temporary cardiac pacing was successfully performed in 94% of the 54 patients studied, demonstrating its feasibility and safety without serious complications.

The procedure had a mean execution time of about 11.3 minutes and required fewer resources compared to traditional methods, making it a potentially advantageous alternative for urgent cardiac pacing.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Temporary emergency cardiac pacing under continuous echocardiographic control. Feasibility and safety of the procedure without using fluoroscopy]. Pinneri, F., Mazza, A., Garzaro, L., et al.[2006]

Temporary cardiac pacing is an effective treatment for various arrhythmias, with atrial pacing being a safer and potentially more effective option than the more commonly used right ventricular pacing.

There are three distinct methods of pacing—interruption, overdrive suppression, and rapid atrial stimulation—each tailored to specific types of arrhythmias, making pacing particularly beneficial for acute recurrent arrhythmias.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The use of pacemaking for the treatment of acute arrhythmias. 2. Preston, TA.[2007]

Dual chamber pacing can significantly improve exercise ability in patients with atrioventricular block who maintain adequate sinus node function, compared to fixed-rate ventricular pacing.

For patients with chronotropic failure or atrial fibrillation, rate-responsive pacing using various sensors (like pH and respiratory rate) allows for adjustments in pacing rates based on metabolic needs, enhancing their overall cardiac function during exercise.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Biosensors and rate-responsive cardiac pacing]. Rodríguez García, J., Silvestre García, J., Coma Samartín, R., et al.[2006]

In a study of 605 patients with a history of high ventricular pacing, 11.7% developed persistent atrial tachyarrhythmias (AT/AF) after 2 years, indicating a significant risk associated with long-term ventricular pacing.

Factors such as prior AT/AF and a ventricular pacing percentage of 10% or more in the first 3 months were identified as independent predictors for developing persistent AT/AF, suggesting that minimizing right ventricular pacing could be beneficial, especially in patients with normal AV conduction.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Association between ventricular pacing and persistent atrial fibrillation in patients indicated to elective pacemaker replacement: Results of the Prefer for Elective Replacement MVP (PreFER MVP) randomized study. Ricci, RP., Botto, GL., Bénézet, JM., et al.[2016]

Transcutaneous cardiac stimulation was successfully used on eight neurocritical patients as a non-invasive alternative to traditional intravenous pacing, proving to be both safe and effective.

The only side effect reported was minor discomfort in conscious patients, highlighting the technique's overall safety profile.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Noninvasive temporary cardiac pacemaker in neurologic intensive care patients]. Hund, E., Rieke, K.[2015]

Temporary cardiac pacing techniques have evolved, with methods like transvenous pacing and noninvasive transcutaneous pacing being highlighted for their effectiveness; however, noninvasive pacing can cause discomfort for unsedated patients.

In patients with implanted pacemakers, temporary pacing can either improve or worsen heart function, necessitating careful preoperative management to avoid complications, such as reprogramming rate-responsive functions and deactivating defibrillators.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Cardiac pacemakers and implantable cardioverter-defibrillators in the perioperative phase]. Kemnitz, J., Peters, J.[2007]

Recent advancements in cardiac pacing technology have shifted from outdated mercury-zinc batteries to more efficient lithium, rechargeable, and isotopic power sources, enhancing the reliability and longevity of pacing systems.

While ventricular pacing remains the standard treatment for symptomatic bradycardia, there is ongoing research into experimental pacing systems that may help manage tachyarrhythmias, indicating a potential expansion of pacing applications in cardiac care.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cardiac pacing. Smyth, NP.[2019]

Electrical pacing is a crucial technique for treating tachycardias, especially when drug therapy fails, and its effectiveness depends on understanding the specific mechanism of the tachycardia.

Pacing near the origin of the tachycardia can enhance suppression, and various pacing methods can improve heart performance or slow down the heart rate without eliminating ectopic pacemaker activity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Tachycardias and electrical pacing. Cohen, HC., Arbel, ER.[2019]

Temporary right atrial pacing can be an effective acute treatment for both bradyarrhythmias and tachyarrhythmias in patients experiencing cardiogenic shock.

This method helps restore atrioventricular synchrony, which is crucial for improving cardiovascular hemodynamics in these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Utility of atrial temporary pacing as an acute treatment for bradyarrhythmias and tachyarrhythmias in the intensive care setting with preservation of atrioventricular synchrony. Pang, B., Everest, E., McGavigan, AD.[2018]

References

1. Poland pubmed.ncbi.nlm.nih.gov

Flow disturbances in carotid and vertebral arteries in symptomatic patients referred for pacemaker implantation. [2016]

2. United States pubmed.ncbi.nlm.nih.gov

Recent advances in artificial pacemakers. [2018]

3. Italy pubmed.ncbi.nlm.nih.gov

[Temporary emergency cardiac pacing under continuous echocardiographic control. Feasibility and safety of the procedure without using fluoroscopy]. [2006]

4. United States pubmed.ncbi.nlm.nih.gov

The use of pacemaking for the treatment of acute arrhythmias. 2. [2007]

5. Spain pubmed.ncbi.nlm.nih.gov

[Biosensors and rate-responsive cardiac pacing]. [2006]

6. United States pubmed.ncbi.nlm.nih.gov

Association between ventricular pacing and persistent atrial fibrillation in patients indicated to elective pacemaker replacement: Results of the Prefer for Elective Replacement MVP (PreFER MVP) randomized study. [2016]

7. Germany pubmed.ncbi.nlm.nih.gov

[Noninvasive temporary cardiac pacemaker in neurologic intensive care patients]. [2015]

8. Germany pubmed.ncbi.nlm.nih.gov

[Cardiac pacemakers and implantable cardioverter-defibrillators in the perioperative phase]. [2007]

9. Netherlands pubmed.ncbi.nlm.nih.gov

Cardiac pacing. [2019]

10. United States pubmed.ncbi.nlm.nih.gov

Tachycardias and electrical pacing. [2019]

11. Australia pubmed.ncbi.nlm.nih.gov

Utility of atrial temporary pacing as an acute treatment for bradyarrhythmias and tachyarrhythmias in the intensive care setting with preservation of atrioventricular synchrony. [2018]