I Woke Up With Intense (left) Shoulder Pain Whenever I

I woke up with intense (left) shoulder pain whenever I extended my arm any direction, whenever I am fighting gravity. I have arthritis but there doesn't seem to be any bone-to-bone contact right now. If I rest the arm (elbow) on the bed, the pain reduces to an moderate ache. (I have had a stent for LAD blockage five years ago.)