A cardiac pacing device, comprising: pulse generation circuitry for generating pacing pulses; sensing circuitry for sensing cardiac electrical activity; a controller for detecting cardiac events that define pacing timing intervals and for controlling the delivery of pacing pulses in accordance with a programmed mode; a switch matrix operable by the controller for connecting the pulse generation circuitry and sensing circuitry to selected electrodes (40 1 -40 N) in order to form selected sensing and pacing channels; wherein the controller is programmed to: sense cardiac activity through a right ventricular sensing channel; schedule delivery of paces through left ventricular pacing channels to at least two left ventricular sites designated LV1 and LV2 during a cardiac cycle interval that is reset by a right ventricular sense; define selected refractory periods such that when a sensing channel is refractory either the sensing channel is disabled or sensed activity is ignored for purposes of cardiac event detection; initiate a post-pace refractory period for the right ventricular sensing channel when the first ventricular pace is delivered during a cardiac cycle; and, after initiation of the post-pace refractory periods for the right ventricular sensing channel when a first ventricular pace is delivered to site LV1, leave the post-pace refractory period unaffected by a subsequent pace to site LV2. pulse generation circuitry for generating pacing pulses; sensing circuitry for sensing cardiac electrical activity; a controller for detecting cardiac events that define pacing timing intervals and for controlling the delivery of pacing pulses in accordance with a programmed mode; a switch matrix operable by the controller for connecting the pulse generation circuitry and sensing circuitry to selected electrodes (40 1 -40 N) in order to form selected sensing and pacing channels; wherein the controller is programmed to: sense cardiac activity through a right ventricular sensing channel; schedule delivery of paces through left ventricular pacing channels to at least two left ventricular sites designated LV1 and LV2 during a cardiac cycle interval that is reset by a right ventricular sense; define selected refractory periods such that when a sensing channel is refractory either the sensing channel is disabled or sensed activity is ignored for purposes of cardiac event detection; initiate a post-pace refractory period for the right ventricular sensing channel when the first ventricular pace is delivered during a cardiac cycle; and, after initiation of the post-pace refractory periods for the right ventricular sensing channel when a first ventricular pace is delivered to site LV1, leave the post-pace refractory period unaffected by a subsequent pace to site LV2. sense cardiac activity through a right ventricular sensing channel; schedule delivery of paces through left ventricular pacing channels to at least two left ventricular sites designated LV1 and LV2 during a cardiac cycle interval that is reset by a right ventricular sense; define selected refractory periods such that when a sensing channel is refractory either the sensing channel is disabled or sensed activity is ignored for purposes of cardiac event detection; initiate a post-pace refractory period for the right ventricular sensing channel when the first ventricular pace is delivered during a cardiac cycle; and, after initiation of the post-pace refractory periods for the right ventricular sensing channel when a first ventricular pace is delivered to site LV1, leave the post-pace refractory period unaffected by a subsequent pace to site LV2.