1. A method for use in an implantable medical device, comprising: storing a first threshold corresponding to detecting a first physiological event; sensing a first physiological signal corresponding to the first physiological event; detecting a plurality of the first physiological events in response to the first physiological signal and the first threshold; storing a second threshold different than the first threshold; determining, in response to detecting at least one of the plurality of the first physiological events, if the second threshold has been met; and enabling detailed monitoring of next ones of the detected plurality of the first physiological events in response to the second threshold being met.