Techniques for applying overdrive pacing to one or both atria following termination of an AF episode, to prevent a recurrent AF episode. An implantable medical device such as a pacemaker applies overdrive pacing according to overdrive pacing parameters, and sets the parameters as a function of the response of the patient to overdrive pacing. The parameters may be adjusted upward or downward, so that overdrive pacing may be applied effectively but not over-applied.