MY MOTHERINLAW IS 90 SHE HAS BEEN BACK AND FORTH

MY MOTHERINLAW IS 90 SHE HAS BEEN BACK AND FORTH TO THE DOCTOR ,ER , AND HOSPITAL SHE HAS BEEN EXPERIENCING CHEST PAIN AFTER AND WHILE EATING ALSO WAS THROWING UP BLACK LOOKING STUFF TO DAY SHE WAS IN ER ALL DAY NOW IN HOSPITAL ROOM , THEY WANT TO HAVE A STRESS TEST DONE TOMARROW ,SHE ALSO HAS THREE STENTS IN SINCE A YEAR AGO . WHAT COULD BE GOING ON WITH HER ? WORRIED!