Study to Evaluate Tetanizing Burst Therapy in Patients Undergoing ICD Replacement

Study Overview
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Brief Summary
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This study evaluates whether the addition of tetanizing burst therapy reduces the pain associated with ICD shocks

Detailed Description
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The implantable cardioverter defibrillator is a device designed to rescue patients from life-threatening arrhythmias by delivering a defibrillation shock to allow restoration of cardiac rhythm. These defibrillation shocks are extremely painful, owing to sudden rapid contraction of thoracic and abdominal skeletal muscle, which, in addition to the heart, are stimulated by the defibrillation shock. Tetanizing Burst Therapy is a novel electrical waveform which tetanizes skeletal muscle with a brief burst of stimulation prior to the ICD shock, thereby reducing muscular contraction due to the shock. This study is designed for those patients who are already undergoing ICD replacement.

Official Title
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Evaluation of the Ongoing Safety and Preliminary Efficacy of the Tetanizing Burst Therapy (TBT) System in Subjects Undergoing ICD Replacement Due to End-of-battery Life

Conditions
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Cardiac Electrophysiology

Intervention / Treatment
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* Device: Tetanizing Burst Therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or Female age 18-80 years, inclusive Ability to understand and provide written informed consent Normal sinus rhythm Standard transvenous left-sided ICD referred for device replacement due to end of battery life Exclusion Criteria: Heart rate <40 or >90 bpm Atrial fibrillation or pacemaker dependent NYHA Class III/IV symptoms of HF MI within 90 days of enrollment Severe cardiac ischemia manifested by chest pain at rest or with minimal exercise History stroke or TIAs History of prior ICD pocket infection ICD lead resistance that is too high or too low in the opinion of the investigator Female who is pregnant or breastfeeding Prior heart transplant Serum electrolytes out of normal range at participating institution

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: Tetanizing Burst Therapy|Tetanizing Burst Therapy tetanizes skeletal muscle with a brief burst of stimulation prior to ICD shock, thereby reducing muscular contraction due to the shock|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Less pain after TBT impulse with ICD shock compared to ICD shock alone | Each subject will receive 2 therapies in random order delivered 5 minutes apart: Tetanizing Burst Therapy + shock; and Pure shock alone. Using the Numeric Pain Rating Scale (NRS) after each shock, the subject will be asked to provide a verbal score between 1 and 10, where 1 is no pain and 10 is the worst pain imaginable. | 5 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The efficacy of tetanizing burst therapy in subjects undergoing ICD replacement as assessed by NRS verbal score | After each shock, a blinded assessor will ask the subject to provide an NRS verbal score between 1 and 10, where 1 is no pain and 10 is the worst pain imaginable. The percent change in the NRS score will be calculated for each subject along with the change in skeletal muscle force waveform | 5 minutes | 
| The safety of tetanizing burst therapy in subjects undergoing ICD replacement as assessed by adverse events | Incidence rates of all adverse events will be calculated and compared to event rates in the literature. They will also be analyzed by severity and relationship to the device and/or study procedures. | 7 days | 
| The device performance of tetanizing burst therapy in subjects undergoing ICD replacement as assessed degree of muscle contraction (Rate of Force Development) | The force of contraction is recorded at the patient's left elbow with a myometer | 5 minutes |