Hello, My sister of 47 years old died suddenly and she had her third pacemaker put in 1 1/2 years ago. Her first pacemaker was put in at her age of 20 because of low heart beat and couldn't repair artery. First two pacemakers worked well, the third was put on the other side of the other two. Had more adjustments than the other two after operation but after a few months she was up and doing very active lifestyle. A few days before her passing she complained of very severe pain in her lower back, butt bone as she put it, and went to Dr. for help. I don't know what Dr. said or did as she went on a trip to Puerto Vallarta with a group of friends for vacation the day after her Dr. visit. She flew there, had a great evening with everyone. Next morning, early, she gets up, gets ready to meet everyone downstairs for breakfast, (early 7 am) met friends in hallway and just fell to the floor. Coronor in Mexico puts heart attack on death certificate. We notified her Dr. of her passing and he simply said "No we didn't know, Duly noted". Should we investigate further?