Hello, Thanks for writing to Health Care Magic, I am Dr Asad Riaz, I have closely read your question and I understand your concerns, I will hereby guide you regarding your health related problem. Heartattack is a conditions in whcih there is no blood supply to heart myocardium n lead to dying of heart muscles..risk factor fo heart attack are age,gender(male female) ,family history,DM,Smoking,HTN etc ,,but pneumonia do not casue heart attack..but if patient laready had heart diseae than infection ca cause acute failure which may lead to death..if u can attch x ray i can able to comment that what he saw on xray ....it can posible ptaient have heart attack n didnt notce n his heart strt faiing like in patient old age,female,DM pain is not present called silent heart attack n this result pateint dont knw that he/she having condition n result heart functions goes down n if pateit have infection this result in acute failure that can lead to death ,n x ray might showed enlarged heart sign of heart failure.. I hope this answered your question, if you have more feel free to ask. Regards. Dr.Asad Riaz. General and Family Physician.