should a PVC reset P timer in DDD mode?

[sevenlayercookie]

If having frequent PVCs, should a PVC interrupt VAI timer?

[sevenlayercookie]

There are multiple ways of handling PVCs. Common ways of framing it is "ventricular-based timing" and "atrial-based timing". Atrial based timing would handle PVCs by extending AEI/VAI interval to mimic compensatory pause (this would be more physiologically correct). However, this allows ventricular rate to drop below LRL in some cases. Plus it's just not super necessary.

So I've implemented ventricular based timing. There is no compensatory pause. VAI timer resets after a PVC with no pause. End effect is that, with frequent PVCs, the pacer will pace leading to an acceleration of average rate.

Ways this could be fixed programmatically: when a PVC is detected, set VAI timer to AA interval - AV interval.