List Item Content Approval notification

I have a list on which I require updates to list items to be approved using the OOTB Content Approval functionality.

When a list item is updated, I would like to notify an approval group to prompt one of the group to take action.  In my scenario, creating a task or using an approval workflow is overkill; I just need a simple notification.

Now I have set a simple SPD workflow to send an email on item change and this works, HOWEVER, once the approver approves the item change, the list item is updated to reflect the approval and this then triggers a further approval request and so the process loops again.

Can anyone offer any advice on their experiences of sending notifications for items requiring approval and make any suggestions about how I should approach this seemingly simple requirement?

Thanks