Drug Effects for Postural Orthostatic Tachycardia Syndrome

Overseen By Bonnie K Black, BSN CNP

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Satish R. Raj

Disqualifiers: Inability to give consent

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

Compensation: Varies

Number of Visits: Unknown

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores why some people feel dizzy or lightheaded when they stand up, a condition known as orthostatic intolerance. Researchers study how this condition affects the heart and circulation, using treatments like DAXOR (a diagnostic tool for blood volume analysis) and Intrinsic Heart Rate. The trial includes two groups: one with healthy individuals to establish a baseline and another with participants who experience these symptoms. Ideal candidates for this trial often feel dizzy or have a racing heart when standing. As an unphased study, this trial offers a unique opportunity to contribute to understanding and potentially improving treatment for orthostatic intolerance.

Do I need to stop my current medications for the trial?

The trial protocol does not specify whether you need to stop taking your current medications.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

In a previous study on DAXOR, researchers found that controlling blood volume is important for treating Postural Orthostatic Tachycardia Syndrome (POTS). The study identified no specific safety concerns, suggesting that DAXOR might be well-tolerated, though further research would be beneficial.

There is no direct safety information about Intrinsic Heart Rate from the sources. However, since heart rate tests often accompany POTS studies, these tests are likely safe and usually don't cause harm.

The QSweat test measures sweating and is non-invasive, meaning it doesn't penetrate the body. While it might feel uncomfortable, it is generally safe and doesn't cause major problems.

Overall, the treatments under study appear safe based on current information, but additional research is always beneficial to confirm this. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores new methods to understand and potentially treat Postural Orthostatic Tachycardia Syndrome (POTS) more effectively. Unlike traditional treatments that focus on symptom management with medications like beta-blockers or increased salt intake, this trial examines DAXOR, Intrinsic Heart Rate, and QSweat to gain insights into physiological responses. By studying these unique approaches, the trial could reveal new mechanisms or biomarkers that improve diagnosis and treatment strategies for POTS, ultimately leading to more tailored and effective interventions.

What evidence suggests that this trial's treatments could be effective for postural orthostatic tachycardia syndrome?

Research shows that treatments for postural orthostatic tachycardia syndrome (POTS) focus on managing symptoms such as a fast heartbeat, dizziness, and tiredness when standing. In this trial, doctors use DAXOR to measure blood volume, gaining insights into blood movement in people with POTS. This information aids in creating personalized treatment plans. Measuring the heart's natural rhythm, another trial aspect, provides insights that may help adjust treatments to improve symptoms. QSweat tests, also part of this trial, assess how the body sweats, which is crucial because POTS can affect blood pressure and temperature control. Although these tools don't directly treat POTS, they are essential for understanding and managing the condition effectively.

Who Is on the Research Team?

David Robertson, M.D.

Principal Investigator

Vanderbilt University

Are You a Good Fit for This Trial?

This trial is for young adults, especially females, who experience rapid heartbeat, fatigue, lightheadedness, and other symptoms when standing up (Orthostatic Intolerance). Participants must be able to give informed consent.

Inclusion Criteria

I feel dizzy or faint when standing up.

Exclusion Criteria

Inability or unwillingness to give informed consent

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Cardiovascular Physiological Studies

Participants undergo cardiovascular physiological studies to describe the mechanism of orthostatic intolerance

6-8 weeks

Follow-up

Participants are monitored for safety and effectiveness after the physiological studies

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• DAXOR
• Intrinsic Heart Rate
• QSweat

Trial Overview The study aims to understand the causes of Orthostatic Intolerance by using cardiovascular physiological tests like DAXOR for blood volume measurement, QSweat for sweat production analysis, and checking intrinsic heart rate.

How Is the Trial Designed?

Group I: Patients Experimental Treatment 3 Interventions

Patients with orthostatic intolerance

Group II: Healthy Control Subjects Experimental Treatment 3 Interventions

Healthy subjects to determine "normal" response

Who Is Running the Clinical Trial?

Satish R. Raj

Lead Sponsor

Trials

7

Recruited

690+

National Institutes of Health (NIH)

Collaborator

Trials

2,896

Recruited

8,053,000+

Published Research Related to This Trial

In a study involving 54 patients with POTS, low-dose propranolol (20 mg) significantly reduced heart rates and improved symptoms compared to placebo, indicating its efficacy as a treatment option.

Higher doses of propranolol (80 mg) resulted in greater reductions in heart rate but did not provide additional symptom relief and may have worsened symptoms, suggesting that lower doses may be more beneficial for managing POTS.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Propranolol decreases tachycardia and improves symptoms in the postural tachycardia syndrome: less is more. Raj, SR., Black, BK., Biaggioni, I., et al.[2021]

In a study of 27 children with postural orthostatic tachycardia syndrome, ivabradine led to symptom improvement in 67% of patients, particularly reducing syncope/presyncope by 90%.

Ivabradine significantly lowered heart rates in both sitting and standing positions without causing significant changes in blood pressure, although some patients experienced mild side effects like visual disturbances and bradycardia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ivabradine in children with postural orthostatic tachycardia syndrome: a retrospective study. Towheed, A., Nesheiwat, Z., Mangi, MA., et al.[2021]

Postural orthostatic tachycardia syndrome (POTS) is a common cause of dizziness in young people, often misdiagnosed as anxiety due to its symptoms, which can lead to years of undiagnosed issues.

The paper discusses various treatment strategies for POTS, including both conservative and pharmacologic approaches, while also exploring the condition's complex cardiovascular mechanisms and the physiological basis of heart rate variability.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Postural Orthostatic Tachycardia Syndrome Misdiagnosed as Anxiety: A Case Report with a Review of Therapy and Pathophysiology. Kesserwani, H.[2020]

In a study of 708 patients with postural orthostatic tachycardia syndrome, various medications were found to effectively manage symptoms, with success rates of 52.2% for light-headedness and 53.4% for pain.

The study highlighted that while insomnia treatment was more effective in females, other symptom therapies showed no gender differences, indicating that medications can be tailored to individual symptoms for better management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Utilisation of medications to reduce symptoms in children with postural orthostatic tachycardia syndrome. Boris, JR., Bernadzikowski, T.[2019]

Citations

1. daxor.com daxor.com/wp-content/uploads/2014/10/raj_renin-aldosterone_circulation_2005.pdf

Arrhythmia/Electrophysiology Background—Patients with postural tachycardia syndrome (POTS) experience considerable disability, but in most, the pathophysiology remains obscure.

2. daxor.com daxor.com/newly-published-study-demonstrates-clinical-utility-of-%E2%80%A8daxors-blood-volume-bva-100-diagnostic-in-the-assessment-of-postural-tachycardia-syndrome-pots/

Newly Published Study Demonstrates Clinical Utility of ... This study shows the crucial need to identify and manage shifts in blood volume in order to guide optimal treatment and outcomes in POTS patients.

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8103825/

Effect of High Dietary Sodium Intake in Patients with Postural ... We tested whether a high sodium (HS) diet reduces orthostatic tachycardia (ΔHR) and upright heart rate (HR) compared with low sodium (LS) diet in POTS patients.

4. dysautonomiainternational.org dysautonomiainternational.org/page.php?ID=30

Postural Orthostatic Tachycardia Syndrome The current diagnostic criteria for POTS is a heart rate increase of 30 beats per minute (bpm) or more, or over 120 bpm, within the first 10 minutes of standing ...

5. ahajournals.org ahajournals.org/doi/10.1161/circulationaha.112.144501

Postural Tachycardia Syndrome (POTS) | Circulation Patients can present with orthostatic hypotension (seen in autonomic nervous system failure) or with orthostatic tachycardia (seen in POTS).