Abstract: This disclosure relates to fault tolerant instantiations of a cardiac therapy delivery device such as an implantable cardiac stimulator (e.g., an implantable pulse generator, IPG, and/or an implantable cardioverter-defibrillator, ICD) coupled to an implantable physiologic sensor (IPS). According to the disclosure delivery of cardiac pacing and/or cardioversion-defibrillator therapy delivery can cause errors in output signals from an IPS. Resolution of such errors involves selectively energizing (or disconnecting the output signal from) the IPS during pacing and/or defibrillation therapy delivery. Programmable signal “blanking” in lieu of or in addition to the foregoing also improves the integrity of the output signal (i.e., continuously energize the IPS and ignore parts of the output signal). An ICD having a transient weakness in an insulated conductor used for the IPS signal can likewise have the IPS de-energized and/or blank the IPS output signal during high voltage therapy delivery.