firstly call an ambulance (a little known factis that the person who receives your call will advise you through the first aid procedure) some things that you may notice in the casualty that may indicate a heart attack: -sweting -chest pain -weakness -nausia sit the casualty down and loosten any restrictive cloathing so that they can breath more easyly give normal dose of asprin (read the packet for correct dose) await the ambulance and continue to moniter the casualty if they do go unconcius and their breathing and or pulse stops (if one stops they both will in a short amount of time) comence CPR give two breaths into their mouth, make sure the breaths are effective enough to make the chest rise and fall place your hands on their sternum (middle of their chest) and press down about the width of a packet of match sticks 30 times after this give two breaths and continue with the compressions untill the ambulance arrives or the person regains conciousness it is always best enroll in a first aid course, it could save the life or you or someone you know