A cardiac interface device helps program an implantable cardiac rhythm or function management device, such as to reduce unnecessary ventricular pacing to avoid contributing to the advancement of heart failure disease progression. An intrinsic conducted AV interval is measured for at least one heart rate, and is predicted or measured for other heart rates. One or more of an age-predicted upper rate limit, a measured sensed AV offset, a PVARP based on measured retrograde conduction time can be used to determine an AV search hysteresis control parameter, and a resulting ventricular interval is graphically displayed relative to the intrinsic conducted AV interval at various heart rates. Confidence intervals or percentage ventricular pacing can also be displayed. Separate graphs for sense and pace initiated AV intervals can be provided.