A method carried out by a therapeutic implantable medical device includes detecting a plurality of physiologic episodes and recording a set of diagnostic data associated with the plurality of physiological episodes. The plurality of physiologic episodes are prioritized based on episode types associated with the physiologic episodes. The diagnostic data is analyzed based on a minimum and maximum number associated with each episode type relating to a minimum and maximum number of sets of diagnostic data to be recorded for the associated episode type. The recorded set of diagnostic data is deleted only if a later recorded set of diagnostic data is associated with a detected physiologic episode having an episode type of a higher priority, and deletion of the set of diagnostic data would not result in fewer sets of diagnostic data than the minimum number specified for the episode type associated with the set of diagnostic data.