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.
