I've mentioned this before in another post, but we use the following SQL statement as an ADO user experience monitor within ipMonitor.
select ServerName, KeepAlive, GetDate(), DateDiff(second, KeepAlive, GetDate()) from [dbo].[Engines] where DateDiff(second, KeepAlive, GetDate()) > 60
If the row count returned is > 0, then at least one of your pollers hasn't updated the database within 60 seconds (indicating an issue with the polling process).
I think that this could also be adapted to run from the APM module that you have.