I HAD A CATH DONE , THERE WHERE NO BLOCKAGE, BUT THE HEART IS STILL RACING, I FEEL LIKE SOME ONE IS SITTING ON MY CHEST, AND I HAVE CHEST PAIN. I DO HAVE HIGH BLOOD PRESSURE AND CHOLOSTROL, AND TAKE MEDS, FOR THOSE, THE DR. GAVE ME PLAVIX AND NITRO TO TAKE, DOES ANYONE HAVE ANY SUGGESTION ON WHAT THIS IS?