Optimized RF telemetry transmission between an active implantable medical device and a remote external receiver in which the information to be transmitted are grouped by class (TYPE 0, TYPE 1, . . . , TYPE n) according to a criticality index (IC) defining a priority rank as between the different information classes to be transmitted. A plurality of modulation schemes and of data rates characterize different transmission configurations, each with a reliability index inversely related to the probability of failure of transmission in a noisy environment. The criticality indexes of the highest priorities are assigned to the transmission configurations with the higher reliability indexes. On an information transmission request, an RF telemetry transmission configuration is selected (52-62) depending on the criticality index characterizing the information to be transmitted. The transmission is operated (64, 66) with the transmission configuration thus selected.