A cardiac rhythm management system includes techniques for computing an
indicated pacing interval, AV delay, or other timing interval. In one
embodiment, a variable indicated pacing interval is computed based at
least in part on an underlying intrinsic heart rate. The indicated pacing
interval is used to time the delivery of biventricular coordination
therapy even when ventricular heart rates are irregular, such as in the
presence of atrial fibrillation. In another embodiment, a variable filter
indicated AV interval is computed based at least in part on an underlying
intrinsic AV interval. The indicated AV interval is used to time the
delivery of atrial tracking biventricular coordination therapy when
atrial heart rhythms are not arrhythmic. Other indicated timing intervals
may be similarly determined. The indicated pacing interval, AV delay, or
other timing interval can also be used in combination with a sensor
indicated rate indicator.