Came here to ask this very same question.
We have several ESX hosts that send a heartbeat trap every ~5 minutes or so.. I'm trying to work out a way to configure something that will alert if this isn't received in a given time-frame (from unique devices) so that the device in question can be health checked.
Due to the fact that we do have several of these devices I really want to have a 'catch all' type alert in place so that when new devices are added, these get picked up automatically (rather than adding rules in on a device by device basis).
If there is some 'workaround' or 'hack' that can be done using Advanced Alert Manager, I'd be keen to get some details around this so I can look to setup something similar...
Thanks,
Daniel