Introduction: Left-ventricular assist devices (LVAD) are becoming a common therapy for end-stage heart failure. These devices are not tested for pressurization in a hyperbaricchamber by the manufacturer. In this article, we present an approach to modify the power supply in order to safely treat a patient with an LVAD. Materials and Methods: Our patient had a HeartMateII LVAD and presented for hyperbaric oxygen treatments for severe radiation cystitis. In order to modify this patient's equipment to be compliant with NFPA6 safety standards we made several modifications. In brief, this included eliminating the usage of lithium-ion batteries, modifying the cord to be compatible with Fink chamber outlets, and enclosing the power module in a nitrogen purge. We then used a mock circulatory system to test our modifications and make sure the LVAD continued to have appropriate flow rates. We then conducted training for staff and developed a disaster plan should the LVAD fail at any point. Results: Once we felt comfortable with the modifications and had a plan developed should any problems arise, we then proceeded to treat our patient in the hyperbaric chamber. He successfully underwent 44 hyperbaric treatments for radiation cystitis without complications. Conclusion: This case is the second reported patient in the literature with an LVAD that was successfully treated in a multiplace hyperbaric chamber. As LVADs become increasingly popular to manage heart failure, more patients with these devices will present for hyperbaric treatments. With a few modifications, an LVAD patient can be safely and successfully treated in a hyperbaric chamber.