I am here for my father. He is 45 years old and he is a high blood pressure patient for the past 3 years now. His blood pressure reading about a week ago was 140/100 which is a cause of concern for me. The doctor has clearly stated that anything above 100 of diastolic blood pressure could be fatal for his life. I want to know beforehand about the signs of heart attack so that we can be prepared for any situation.