Lo Bat for Implantable Cardiac Defibrillators

Medtronic warned physicians today about the possibility of battery failures in one of its models of implantable cardiac defibrillators (ICDs), 87,000 of which were manufactured before 2003. The market for these devices has recently expanded, since Medicare approved their prophylactic use for patients with congestive heart failure. Medicare planned to pay from $28 to $36K for the device, and the procedure to implant it.
I believe (but cannot find evidence at the moment to prove) that the price of the actual ICD is around $25K. If so, given that its circuitry cannot be that complex in this day and age, one would think that this would have been enough to buy an extremely reliable battery.
This reinforces the questions I recently raised about the pricing of medical devices versus their value to the patient.