SignalR broadcast using Entity Framework and Unit of Work

I will be working in the remaking of an old legacy project. The new implementation will use EntityFramework and Unit of Work.

In the old project there are a lot of popups that show up when some value changes in the database. This is implemented with constant polling and logic checking if the value is different from the last one cached. As you can see this is slowing the project a lot.

For the new one I'll like to explore the best options to send SignalR notification when some particular models change in the database in the context of Unit of Work. I have some ideas but they don't seem good enough to me.

Can you give me sample implementation of some good practice in such scenario?