“Pacemakers from Abbott Laboratories contain critical flaws that allow hijackers within radio range to seize control while the pacemakers are running. The update will require patients to visit a clinic where doctors will put the pacemakers in backup mode while the firmware is being patched. The Abbott letter said that, for certain patients, the update should be performed ‘in a facility where temporary pacing and pacemaker generator change are readily available, due to the very small estimated risk of firmware update malfunction.’”