Last year I took my father to see his cardiologist. He decided to hook him up to a heart monitor. THe monitor went off at least 4 times before we left

10 days later he died of a heart attack. My concern is that the heart monitor went off 4 to 10 times a day with no call from the doctor. When he died he was at a softball tournament with my 16 year old. He was having chest discomfort. The monitor went off so my daughter phoned it in to the company. She told them he was having chest pain and shortness of breath. They told her he was fine that nothing showed on the monitor to reset it. She still called 911 but 15 minutes later he was dead. I think there is negligence that the doctor didnt do anything since the heart monitor leads were sent to him and I think the heart monitoring place was negligence in either equipment and what they advised my daughter. This is a large cardiologist group in my state so I''m not sure who would take this if I have a case. Advise?