Patent ID: 8880172

Claim:
A method, comprising: performing atrial capture threshold testing in accordance with an atrial capture threshold testing schedule, wherein the atrial capture threshold testing includes delivering a plurality of pacing pulses to an atrium, the atrial capture threshold testing schedule defines regularly occurring predetermined times at which scheduled atrial capture threshold testing is performed, wherein atrial capture threshold testing comprises decreasing a pacing energy of the plurality of pacing pulses in discrete steps until loss of capture occurs or increasing pacing energy of the plurality of pacing pulses in discrete steps until capture occurs; monitoring for retrograde P-waves between two of the regularly occurring predetermined times of the atrial capture threshold testing schedule; detecting, during the monitoring, a retrograde P-wave indicative of sub-threshold atrial pacing; and adjusting pacing of the atrium in response to detecting the retrograde P-wave, wherein adjusting pacing of the atrium includes adjusting a pacing pulse amplitude and/or a pacing pulse width.