What Causes Heart Palpitations With Normal EKG And Stress Test?

I have high blood pressure and acid reflux so I was told when hospitalized a month ago for chest pains and BP over two hundred. Am on lisinipril, omeprazole and a water pill. I have had palpitations and racing feeling several times in past month, along with chest burning, fullness and squeezing like pressure. Taking a baby aspirin helps with the palpitations, it was what worked when in hospital at start if this a month ago. . I have had a stress test, several ekgs and lung x rays, all came back normal. Is this all acid reflux? It does not only occur immediately after a meal. What doctor should I see? The cardiologist cleared me and does not need to see me he said.