My dad (79, 200 lbs+) had an angiogram and angioplasty last week. They inserted 2 stints into the arteries of the heart, after finding 2 70% blockages. 2 days after the procedure he had a terrible burning throat that has been burning still, 4 days later (gradually less). Today he was able to eat more than liquid and soft foods for the first time. (He has had acid reflux in the past, but says this is not acid reflux.) Any ideas what may be causing this???