Pacing systems are disclosed including detectors for detecting the presence of electromagnetic interference and setting an interference state pacing mode and pacing rate. The interference state pacing mode and pacing rate are altered as a function of patient pacemaker dependency and the prevailing mean heart rate. When pacemaker dependency exists, the pacing rate is maintained and even increased from the prevailing mean heart for the duration of the interference state. When the patient is determined to not be pacemaker dependent, pacing is inhibited or suspended for the duration of the interference state.