GANGlion Stellate Block for Treatment of Electric storRm (GANGSTER Trial)

Study Overview
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Brief Summary
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This study will evaluate the acute effect of ultrasound-navigated left ganglion stellate block to suppress ventricular arrhythmia in patients with arrhythmic storm.

Detailed Description
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The study will include patients with drug-refractory arrhythmic storm indicated for left ganglion stellate block (LGSB) before or after catheter ablation. Included participants will be dived based on the need for mechanical ventilation and catheter ablation performed <5 days before the study Subsequently, the participants will be randomized to LGSB or to a sham (placebo) procedure. The primary endpoint will be a reduction of the burden of clinical arrhythmia >50% 24 hours after LGSB without escalation of antiarrhythmic therapy. The study will include 80 patients over 4 years.

Official Title
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Ganglion Stellate Block for Treatment of Electric Storm - a Randomized Study

Conditions
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Ventricular Tachycardia, Ventricular Fibrillation, Arrhythmic Storm, Block, Ventricular Arrythmia

Intervention / Treatment
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* Procedure: Left ganglion stellate block
* Procedure: Sham left ganglion stellate block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: arrhythmic storm <24 hours before inclusion: 3 or more episodes of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) terminated by external or internal shock, or incessant VT lasting >30 minutes, or very frequent nonsustained or sustained VT leading to hemodynamic instability with the need of escalation of the therapy clinical indication for LBGS based on the judgment of the physician, independent of the study Exclusion Criteria: known allergy to bupivacaine prior LBGS performed <7 days before the study known reversible provoking trigger of the arrhythmias ventricular arrhythmias triggered by premature ectopic beats during bradycardia hemodynamically tolerated idiopathic VT in patients without structural heart disease

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomization 1:1 for active treatment vs. sham procedure
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Actual LGSB<br>The patients will receive an actual LGSB procedure: Using ultrasound navigation and an echo-contrast needle, 8ml of bupivacain (5%) will be applied to the site of the left ganglion stellate through an anterolateral approach in the neck region. | Procedure: Left ganglion stellate block<br>* Ultrasound-guided anesthetic block of left ganglion stellate using 8ml of 5% bupivacaine.<br>|
| Sham Comparator: Sham procedure<br>The procedure will be performed using the same instruments and anesthetic drug as the actual LGSB. However, the operator will apply only 0.5-1ml of the anesthetic drug and only subcutaneously to the site where an actual LGSB would be performed. | Procedure: Sham left ganglion stellate block<br>* Subcutaneous application of 0.5-1ml of 5% bupivacaine to the site of expected LGSB<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the number of episodes of sustained VT/VF | Change by >50% of the number of episodes of sustained ventricular tachycardia/fibrillation compared to 24 hours before LGSB, without escalation of antiarrhythmic therapy during 24 hours after LGSB (deep sedation requiring mechanical ventilation, addition of another antiarrhythmic drug, implantation of mechanical circulatory support, unplanned emergent catheter ablation) | 2-24 hours after LGSB. The first 2 hours after the LGSB will not be considered in the evaluation (i.e., blanking period) | 
| Change in arrhythmia burden quantified by Holter ECG | Change of the percent of QRS complexes with ventricular tachycardia by >50% on Holter ECG, as compared to 24 hours before LGSB, without escalation of antiarrhythmic therapy during 24 hours after LGSB (deep sedation requiring mechanical ventilation, addition of another antiarrhythmic drug, implantation of mechanical circulatory support, unplanned emergent catheter ablation). | 2-24 hours after LGSB. The first 2 hours after the LGSB will not be considered in the evaluation (i.e., blanking period) |