A medical device is configured to sense at least one cardiac electrical signal and generate pacing pulses according to a first pacing therapy by generating pacing pulses for delivery to a first combination of ventricular pacing sites including at least one ventricular conduction system pacing site. The medical device may be configured to determine a ventricular conduction condition based on a QRS signal feature of the sensed cardiac signal during the first pacing therapy. The medical device may change to a second pacing therapy different than the first pacing therapy based on the determined ventricular conduction condition.