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

NCT07837804 | Not Yet Recruiting

• 1 other identifier: 0120-209/2026-2711-3
• Study Type: interventional
• Target: 30
• Locations: 0 countries
• Sites: N/A

Brief 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. 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.

Conditions

POTS - Postural Orthostatic Tachycardia Syndrome

Keywords

Postural orthostatic tachycardia syndrome; POTS; Autonomic dysfunction; Stellate ganglion block; Sympathetic nervous system; Sympathetic neuromodulation; Multidomain phenotyping

Outcome Measures

Primary Outcomes (7)

• Completion of the Core Phase 1 Phenotyping Protocol

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

  End of Phase 1 phenotyping (before stellate ganglion block)

• 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.

  End of Phase 1 phenotyping (before stellate ganglion block)

• 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.

  At initiation of Phase 2 (stellate ganglion block)

• 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.

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

• Completion of First Follow-up

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

  Approximately 14 days after completion of bilateral stellate ganglion block

• Completion of Second Follow-up

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

  Approximately 3 months after completion of bilateral stellate ganglion block

• 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.

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

Secondary Outcomes (1)

• Technical Success of Stellate Ganglion Block

  Within 30 minutes after each stellate ganglion block procedure

Other Outcomes (5)

• Change in Orthostatic Heart Rate Increment

  Baseline and approximately 14 days and 3 months after completion of bilateral stellate ganglion block

• Change in Mean Standing Heart Rate

  Baseline and approximately 14 days and 3 months after completion of bilateral stellate ganglion block

• Change in Standard Deviation of Normal-to-Normal Intervals (SDNN)

  Baseline and approximately 14 days and 3 months after completion of bilateral stellate ganglion block

Study Arms (2)

Participants with POTS

EXPERIMENTAL

Participants 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.

Procedure: Bilateral Sequential Stellate Ganglion Block

Healthy controls

NO INTERVENTION

Healthy 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.

Interventions

Bilateral Sequential Stellate Ganglion Block PROCEDURE

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.

Also known as: SGB

Participants with POTS

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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:
• 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.

You may not qualify if:

• 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.
• 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.

Sponsors & Collaborators

• University Medical Centre Ljubljana: lead

MeSH Terms

Conditions

Postural Orthostatic Tachycardia Syndrome; Primary Dysautonomias

Condition Hierarchy (Ancestors)

Orthostatic Intolerance; Autonomic Nervous System Diseases; Nervous System Diseases

Study Officials

• Bor Antolic, MD

  University Medical Centre Ljubljana

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Bor Antolic, MD, PhD

CONTACT

041325796; bor.antolic@kclj.si

Rok Herman, MD

CONTACT

051604844; rok.herman@kclj.si

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 10, 2026
• First Posted: September 24, 2026
• Study Start: October 1, 2026
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: September 24, 2026

Record last verified: 2026-08