My Daughter Passed Away Last April. She Had A Heart

My daughter passed away last April. She had a heart attack 5 yrs before and 1/3 of her heart was damaged. The physician said he could not put a stent in because the blockage was so hard. Then she just fell to the floor at work and did not respond. When I got to the ER,, she was already turning dark blue and blood and fluid was coming out of her nose and her body was swollen 3 times its size. What could have caused that?