You could try and Advanced alert, use a custom SQL alert, select the type of property to monitor of Node, then add this into the text box.
Join Traps on Traps.NodeID = Nodes.NodeID
Where Traps.DateTime > DATEADD(MINUTE , -5, GetDate)
And Traps.TrapType LIKE '%vmwCimOmHeartbeat'
You can also test the query by using this query in the Database Manager or SQL Server Management Studio.
Select Nodes.Caption, Nodes.IP_Address from Nodes
Join Traps on Traps.NodeID = Nodes.NodeID
Where Traps.DateTime > DATEADD(MINUTE , -5, GetDate)
And Traps.TrapType LIKE '%vmwCimOmHeartbeat'
May get you what you are looking for.