An implantable cardiac rhythm management device for delivering anti-tachyarrhythmia therapy is provided with a temporary disablement feature so that the delivery of anti-tachyarrhythmia therapy may be conveniently disabled and re-enabled. The feature is particularly useful to patients who are undergoing imaging procedures or surgical procedures where electro-cauterizing instruments may cause inadvertent triggering of cardioversion/defibrillation shocks and/or anti-tachycardia pacing.