I had this same pain for twenty years. Every time I had this sharp pain between the shoulder
Blades. And each time they found a heart blockage. Angioplasty/bypass/stenting. Said it was angina. But even after all that treatment the pain still existed. Many doctors have said it was trapped gas, low potassum, /reflux. My gallblader was checked/lungs were okay.

But the pain still exist today. The only new recent development they found an arthritic condition on my spine.

The pain remands a mystery.

My guess is the pain is from all of your problems. When you have a lot of things like that going on in your body it stands to reason that the 'ill' parts of your body are putting a strain on your entire body and it is going to effect you. Like if you carry a load in your arms your back gets strained, if you carry a load on your back your legs get strained.

Are you taking meds for your heart and acid reflux?
There are different supplements you can take for your heart and reflux depending on what meds you take.

One thing you can take with each meal is digestive enzymes.