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POTS - Postural Orthostatic Tachycardia SyndromeRESET-POTSNCT07837804

RESET-POTS: Multimodal Phenotyping and Stellate Ganglion Block in Postural Orthostatic Tachycardia Syndrome

A study testing Bilateral Sequential Stellate Ganglion Block in people with POTS - Postural Orthostatic Tachycardia Syndrome, run by University Medical Centre Ljubljana.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

RESET-POTS is a pilot study for adults with postural orthostatic tachycardia syndrome (POTS), a condition that can cause a rapid increase in heart rate, dizziness, weakness, fatigue and other symptoms when standing. The study has two parts. Read more about this study

Who is it for?
Ages 18 to 65 yearsHealthy volunteers can take part
What is being tested?
Bilateral Sequential Stellate Ganglion Block
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
30 participants
Where
No sites listed yet
Study dates
1 Oct 2026to Dec 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 65 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Participants with POTS:
  • Age 18 to 65 years.
  • Confirmed diagnosis of postural orthostatic tachycardia syndrome (POTS) by a cardiologist or neurologist within the previous 3 years.
  • Persistent symptoms of orthostatic intolerance despite or regardless of current medication use.
  • Ability to understand the study procedures and provide written informed consent.
  • Healthy control participants:
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  • Age 18 to 65 years.
  • Where feasible, matched to the POTS group according to age, sex, and body mass index category and, in premenopausal women, menstrual-cycle phase.
  • No known chronic disease.
  • No regular use of medication that could substantially affect autonomic, endocrine, or metabolic measurements.
  • Ability to understand the study procedures and provide written informed consent.

Who cannot join

  • For all participants:
  • Pregnancy or breastfeeding.
  • Active acute infection at the time of assessment.
  • Significant comorbidity that could confound interpretation of study findings or increase procedural risk, including: type 1 or type 2 diabetes mellitus; heart failure; significant valvular heart disease; clinically relevant renal impairment; clinically relevant hepatic impairment; peripheral neuropathy; known central nervous system disease.
  • Contraindication to any study procedure.
  • An identified alternative explanation for orthostatic symptoms or tachycardia, including significant anemia, dehydration or hypovolemia, acute febrile illness or infection, hyperthyroidism, primary adrenal disease, a primary anxiety or panic disorder considered to be the principal cause of symptoms, or medication-induced tachycardia.
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  • Additional exclusion criteria for the stellate ganglion block phase:
  • Previous stellate ganglion block.
  • Known allergy or hypersensitivity to amide local anesthetics.
  • Current therapeutic anticoagulation or known bleeding disorder.
  • History of glaucoma.
  • Local infection or relevant anatomical abnormality at the planned injection site.
  • Any clinical condition considered by the investigator or anesthesiologist to make stellate ganglion block unsafe.

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

Bor Antolic, MD, PhD contact

041325796 ext. +386

bor.antolic@kclj.si

About this study

Official title: RESET-POTS: Protocol for a Two-phase Pilot and Feasibility Study of Multidomain Phenotyping and Bilateral Sequential Stellate Ganglion Block in Postural Orthostatic Tachycardia Syndrome

RESET-POTS is a pilot study for adults with postural orthostatic tachycardia syndrome (POTS), a condition that can cause a rapid increase in heart rate, dizziness, weakness, fatigue and other symptoms when standing. The study has two parts. In the first part, patients with POTS and healthy volunteers will undergo several tests to better understand how POTS affects heart rate and blood pressure, the autonomic nervous system, hormones, metabolism, blood sugar regulation, brain and muscle oxygenation, and quality of life. In the second part, eligible patients with POTS will receive a stellate ganglion block, a procedure in which a local anaesthetic is injected near nerves in the neck that are involved in sympathetic nervous system activity. The procedure will be performed on the right and left sides on separate days. Participants will then be reassessed about 2 weeks and 3 months later. The main goals are to determine whether the study procedures are practical and well tolerated, whether the nerve block can be performed successfully and safely, and whether there are signs of changes in POTS-related body functions and symptoms.

Read the detailed description

Postural orthostatic tachycardia syndrome (POTS) is a condition in which standing causes an excessive increase in heart rate together with symptoms such as dizziness, palpitations, weakness, fatigue, exercise intolerance and difficulties with concentration. POTS is a heterogeneous condition, meaning that the underlying abnormalities may differ considerably between individuals. Changes in autonomic nervous system activity, regulation of blood volume and hormones, metabolism, and blood flow or oxygen delivery to the brain may all contribute to symptoms. However, the relationships between these abnormalities are not fully understood, and currently available treatments do not adequately control symptoms in all patients. RESET-POTS therefore focuses on adults with confirmed POTS who remain symptomatic despite standard non-pharmacological and pharmacological management.

The study consists of two phases. In Phase 1, patients with POTS and healthy volunteers will undergo detailed testing designed to provide a broad picture of how the body responds to standing. This includes a 10-minute standing test with continuous measurement of heart rate and blood pressure, assessment of heart-rate variability, and measurement of breathing and oxygenation in the brain and skeletal muscle. Blood samples obtained while lying down and standing will be used to examine hormones and other markers involved in sympathetic nervous system activity, blood-volume regulation and endocrine function. Additional assessments include glucose and insulin responses, continuous glucose monitoring, resting and standing energy expenditure, body composition, muscle strength, cortisol patterns and questionnaires assessing symptoms and quality of life. The aim of this phase is to identify physiological patterns that may help explain why POTS differs between individuals and to identify measurements that could be useful in future treatment studies.

In Phase 2, eligible patients with POTS will receive a stellate ganglion block (SGB). The stellate ganglion is a group of nerves in the neck that forms part of the sympathetic nervous system, which helps regulate heart rate, blood vessels and the body's response to stress. During SGB, a local anaesthetic is injected under ultrasound guidance near these nerves to temporarily reduce sympathetic nerve activity. In RESET-POTS, the right and left sides will be treated during separate procedures approximately 3-7 days apart. Participants will be monitored during and after each procedure. Changes in skin temperature and clinical signs will be used to confirm whether the nerve block has produced the expected physiological effect.

Participants who undergo SGB will repeat relevant assessments approximately 2 weeks and 3 months after completion of the bilateral intervention. The study is not designed to determine conclusively whether SGB is an effective treatment for POTS. Instead, its main goals are to determine whether this approach can be studied safely and practically, whether participants can complete the planned testing and follow-up, whether the SGB procedures can be performed successfully, and whether the collected physiological measurements are sufficiently reliable for a larger future trial. Changes in heart-rate responses to standing, autonomic nervous system activity, hormonal and metabolic measures, brain and muscle oxygenation, and POTS symptoms will also be explored.

The results will be used to design a future randomized, sham-controlled clinical trial. In particular, RESET-POTS aims to help determine which patients may be most suitable for sympathetic nervous system-targeted treatment, which objective measurements should be used to assess treatment effects, and how a larger trial should be designed to distinguish the physiological effects of SGB from placebo and expectancy effects.

Being tested
Bilateral Sequential Stellate Ganglion Block
Keywords
Postural orthostatic tachycardia syndrome, POTS, Autonomic dysfunction, Stellate ganglion block, Sympathetic nervous system, Sympathetic neuromodulation, Multidomain phenotyping
Medical subject headings
Postural Orthostatic Tachycardia Syndrome, Primary Dysautonomias

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Bilateral Sequential Stellate Ganglion BlockProcedure or surgery

    Also called SGB

    Participants will undergo ultrasound-guided stellate ganglion block (SGB) on both sides, performed as two separate procedures 3-7 days apart. The right side will be treated first, followed by the left side. Each block will be performed under real-time ultrasound guidance, primarily at the C6 level, using levobupivacaine 0.5% (8 mL per side), without exceeding the recommended maximum dose. Participants will be monitored during and after each procedure. Technical success of the block will be assessed using infrared thermography and supportive clinical signs of sympathetic blockade.

Study groups in NCT07837804
Study groupRoleWhat they receive
Participants with POTSExperimentalParticipants with confirmed postural orthostatic tachycardia syndrome will undergo comprehensive multidomain phenotyping. Participants who meet the eligibility criteria for the interventional phase will subsequently undergo bilateral sequential ultrasound-guided stellate ganglion block, with the right and left sides treated in separate sessions 3-7 days apart. Follow-up assessments will be performed approximately 14 days and 3 months after completion of the bilateral intervention.
Receives: Procedure: Bilateral Sequential Stellate Ganglion Block
Healthy controlsNo interventionHealthy control participants will undergo the same baseline multidomain phenotyping assessments as the POTS group, where applicable, to provide comparative physiological data. Healthy controls will not undergo stellate ganglion block or post-intervention follow-up assessments.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Completion of the Core Phase 1 Phenotyping Protocol

    Percentage of enrolled participants who complete the predefined core multidomain Phase 1 phenotyping protocol.

    Measured: End of Phase 1 phenotyping (before stellate ganglion block)

  2. Completeness of Phase 1 Phenotyping Data

    Proportion of participants with complete and interpretable data across the predefined phenotyping domains. Data completeness will be assessed to determine the feasibility of using the multidomain assessment battery in a future randomized trial.

    Measured: End of Phase 1 phenotyping (before stellate ganglion block)

  3. Progression of Patients With POTS to the Interventional Phase

    Percentage of eligible patients with POTS who proceed from Phase 1 phenotyping to Phase 2 and undergo stellate ganglion block.

    Measured: At initiation of Phase 2 (stellate ganglion block)

  4. Completion of Both Planned Stellate Ganglion Block Procedures

    Percentage of participants entering Phase 2 who complete both the right and left stellate ganglion block procedures as planned.

    Measured: From the first stellate ganglion block to the second block, performed 3-7 days later

  5. Completion of First Follow-up

    Percentage of participants undergoing bilateral stellate ganglion block who complete the planned early follow-up assessment.

    Measured: Approximately 14 days after completion of bilateral stellate ganglion block

  6. Completion of Second Follow-up

    Percentage of participants undergoing bilateral stellate ganglion block who complete the planned final follow-up assessment.

    Measured: Approximately 3 months after completion of bilateral stellate ganglion block

  7. Incidence of Adverse Events

    Number and percentage of participants experiencing adverse events during the interventional phase, including the type and severity of events and their relationship to stellate ganglion block. Procedure-related events of particular interest include dysphonia, dysphagia, hoarseness, brachial plexus block, phrenic nerve involvement, hematoma, vasovagal reaction, infection, allergic reaction, inadvertent intravascular injection, local anesthetic systemic toxicity, and pneumothorax.

    Measured: From the first stellate ganglion block through the final follow-up approximately 3 months after bilateral stellate ganglion block

Secondary outcomes (1)
  1. Technical Success of Stellate Ganglion Block

    Percentage of performed stellate ganglion block procedures meeting the predefined criteria for technical success. Technical success will be based primarily on thermographic evidence of ipsilateral sympathetic blockade, supported by clinical signs where present.

    Measured: Within 30 minutes after each stellate ganglion block procedure

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Sep 2026
  2. Study start1 Oct 2026 (estimated)
  3. Primary completion1 Oct 2027 (estimated)
  4. Study completionDec 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
30 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07837804
Sponsor's protocol ID
0120-209/2026-2711-3
Acronym
RESET-POTS
Status last verified
Aug 2026
First submitted
10 Aug 2026
Last updated
24 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

A study testing Bilateral Sequential Stellate Ganglion Block in people with POTS - Postural Orthostatic Tachycardia Syndrome, run by University Medical Centre Ljubljana.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 11 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Bor Antolic, MD, PhD (041325796 ext. +386, bor.antolic@kclj.si), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Completion of the Core Phase 1 Phenotyping Protocol (time frame: End of Phase 1 phenotyping (before stellate ganglion block)). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Sep 2026.

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