This study is a non-randomized, prospective study in patients with a diagnosis of epilepsy and previously implanted FDA approved Vagus Nerve Stimulation (VNS) devices. The goal of this clinical investigation is to evaluate the effects of adjusting vagus nerve stimulation parameters to engage cardioprotective effects.

Epilepsy patients are at increased risk for sudden cardiac death. Mechanisms behind this predisposition is poorly understood but parasympathetic dysfunction is heavily implicated. Vagus Nerve Stimulation (VNS) protocols currently set for seizure management are poorly optimized for cardioprotection, therefore this patient population presents a unique opportunity to assess VNS control of cardiac function, when VNS is appropriately titrated for cardiac and seizure benefit.

This study will enroll 12 patients with a diagnosis of epilepsy and previously implanted FDA approved VNS devices. The study will last up to 9 weeks and the patient will undergo changes to their VNS settings during autonomic testing and cardiopulmonary testing.

Inclusion Criteria:

• Clinical diagnosis of refractory epilepsy and implanted with a VNS device or are scheduled to be implanted with a VNS device.
• 18 years of age or older
• Subjects must demonstrate willingness and ability to comply with study requirements

Exclusion Criteria:

• Other implantable neuromodulatory device (e.g., brain stimulator)
• Treatment with cholinergic or anticholinergic medication in the past month
• Pre-existing cardiac arrhythmia or presence of cardiac pacemaker/defibrillator
• History of dysautonomias
• History of vasovagal syncope
• Progressive neurological diseases other than epilepsy
• Women that are pregnant
• Cognitive or psychiatric deficit that in the investigator's judgment would interfere with the subject's ability to accurately complete study assessments

1 Day

Participant completed only one study visit