**4. Conclusions**

Implantable devices, including Implantable Cardiac Defibrillators (ICD) and Pacemakers (PM), are being seen with increasing frequency in patients wanting to conduct recreational diving or referred for Hyperbaric Oxygen Therapy (HBOT). Considering the intrinsic properties of the modern implantable devices, it seems that the residual risk for malfunction while being exposed to maximum pressure of 4 ATA, equivalent to the depth of 30 msw, is extremely low. Greater pressures up to 7 ATA (equivalent to the depth of 60 msw) increase the risk of temporarily deterioration with degradation of the performance. Higher pressures, unlikely to be used either in modern HBOT or in recreational conservative diving, can cause permanent damage of the device; unless specifically tested and confirmed by the manufacturer, such exposures should be avoided.
