These implantable devices have been found to offer benefit to patients that are at a high risk of ventricular tachycardia, ventricular fibrillation or other rhythm defects that can lead to sudden cardiac arrest. The pacemaker feature will increase the heart rate of the patient if it slows to an inefficient rate.
With or without the pacemaker feature, these internal devices are used to treat potentially life-threatening rhythms. It is the opinion of diving medicine professionals that due to the potential life threat individuals with these implanted devices are not recommended for diving.
These devices are intended to prevent sudden cardiac arrest but the heart itself may be in generally poor health which is not compatible with safe diving. As relaxing as diving is there is still an increased work-load placed on the heart when diving. The heart needs to be able to respond effectively to any increased exercise demand, especially in an emergent situation. A heart that is prone to life-threatening rhythms most likely has sustained injury from coronary artery disease or other conditions that affect the muscle tissue of the heart or its electrical pathways. Any exercise restrictions from the diver’s cardiologist would be a good indicator that diving would may not be in their best interest.
To this date limited testing has been performed on the implantable defibrillators regarding the affects of increased ambient pressure. There is an air space in the device and only limited testing is reported to 40fsw. This is not considered to be an adequate testing depth for recreational diving. There is no data available to determine what if any effect increased ambient pressure may have on the function of the device especially in terms of repeat exposures.
Any questions a diver may have regarding their particular situation and fitness to dive may contact DAN Medical Services for information. Physicians are encouraged to contact DAN for consultation with a dive medicine physician.