The baseline rhythm is sinus with complete AV block. Atrial pacing (AP) is occurring, so the VDI and VDD modes can be excluded. The device was programmed in the DDI mode with a baseline rate of 60bpm.
Note that there is loss of AV synchrony with atrial sensed events (AS) at a constant ventricular pacing (VP) rate of 60bpm (the VP–VP intervals are labelled at 996–1000ms, due to cycles of the device clock). This excludes DDD and VDD pacing modes, which track sensed atrial activity. So the Pacing Mode in this tracing is DDI.