Study to Evaluate Tetanizing Burst Therapy in Patients Undergoing ICD Replacement

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.

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 battery
depletion

Exclusion Criteria:

- Heart rate <50 or >90 bpm

- Atrial fibrillation or pacemaker dependent

- QT interval > 500ms

- NYHA Class III/IV

- LVEF <30%

- 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

- Transvenous lead resistance >50Ω

- Known high defibrillator thresholds (DFT) >25J

- Presence of cardiac-resynchronization therapy device (CRT System), or another cardiac
device, except ICD

- Female who is pregnant or breastfeeding

- Prior heart transplant

- Serum electrolytes out of normal range at participating institution