An implantable medical device is configured to detect saturation events from a cardiac electrical signal, detect a tachyarrhythmia based at least in part on the cardiac electrical signal, responsive to detecting the tachyarrhythmia, and compare the detected saturation events to lead issue criteria. If the detected saturation events satisfy lead issue criteria, a therapy for treating the tachyarrhythmia is withheld by the implantable medical device.
