A new defibrillator from Boston Scientific hit the market, eliminating a lot of the risks associated with “implantable” units. The leads of the device do not go directly into the heart but, rather, stay outside, eliminating many surgical risks and related complications.
In 2010, 97,000 cardiac defibrillators were implanted, according to the AHA, so the market seems large. Read more here. Of course, these devices are for people with known cardiac issues. An AED is the best tool for unknown issues to maximize protection.