A medical device and associated method deliver cardiac pacing in a dual chamber pacing mode and schedule an atrial-ventricular (AV) conduction check during the dual chamber pacing mode to detect the presence of AV conduction. If AV conduction is detected during the scheduled AV conduction check, the medical device switches to an atrial pacing mode and switches back to the dual chamber pacing mode in response to an absence of AV conduction during the atrial pacing mode. The detected AV conduction is identified as a false positive detection in response to the pacing mode switch to the dual chamber pacing mode occurring within a predetermined interval of time from detecting the AV conduction.
