Risks of Implanted Defibrillators

An implanted defibrillator, a larger medical device than a pacemaker, prevents death from cardiac arrest. If the patient suffers a life-threatening loss of function in the lower chambers of the heart, the defibrillator shocks the heart into renewed function. Defibrillators also incorporate pacemaker functions, such as slowing a too-rapid heart beat or increasing the rate of a heart beating too slow. The implanted device also presents certain risks, some of them inherent in the normal function of the device, others created by a defective implantation and others still by defects in the device itself.

Electromagnetic Risks

• A defibrillator functions in part by detecting electromagnetic signals emanating from the heart. It may mistakenly interpret an external electromagnetic field as a signal from the heart, and then respond inappropriately--by withholding pace, for example, or by administering a severe shock to a normally functioning heart. In other cases, it may withhold a needed shock because of external electromagnetic interference. If you have an implanted defibrillator, you have to avoid magnetic fields, including the walk-through screening devices found at airport security checkpoints. Many common electronic devices, like cellphones and microwave ovens, can also present some risk.

Physical Risks

• If you have an implanted defibrillator, certain strenuous physical activities, such as weight-lifting and some contact sports, can cause one of the small wires, called leads, to break, disconnecting the device from its battery. In addition to causing the device itself to fail, the lead's broken ends can tear an artery or puncture a heart or lung.

Defective Implantation

• A 2007 study of over 100,000 defibrillator implants found significantly fewer complications related to implantation procedure when performed by electrophysiologists, and almost twice as many complications for procedures performed by thoracic surgeons. Electrophysiologists complete cardiosurgical training, then spend another two years learning specialized procedures like defibrillator implantation. Thoracic surgeons do not specialize in heart surgery, but do receive general surgical training within the chest cavity. You have the best chance of a successful surgery with an experienced board-certified electrophysiologist who practices at a highly-ranked hospital and who performs many of these procedures.

Defective Devices

• Medtronic, a major medical device maker, used defective defibrillator components over an extended period of time. Guidant, another major supplier of defibrillators, lost several suits related to defective debrillators, and received a large fine from the federal government for withholding their knowledge of these defects while continuing to sell devices. Guidant recalled these devices. Guidant, Medtronic and medical insurance companies disputed financial responsibility for replacing the devices, engendering another round of suits. Device like defibrillators, even when designed by a major medical corporation and subjected to extensive testing, may have defects that will not become widely known until patients have suffered and, as in this instance, have died.