The symptoms of a heart attack can be dramatic: severe constricting or bursting pain in the chest, sometimes spreading to the arms, neck, and back; faintness and shortness of breath; irregular pulse; blue lips; collapse and unconsciousness. Breathing and heartbeat may stop. For more information, select Heart Attack.
If the victim remains conscious, prop him or her up in a half-sitting position with knees bent. Dial 911. Calm and reassure the person as much as you can, keep him or her warm and comfortable, loosen any tight clothing, and keep a careful watch on breathing and pulse.
If the casualty is unconscious, check breathing and pulse, and if necessary give artificial respiration and cardiac resuscitation (select Breathing, Circulation). As soon as you judge breathing and heartbeat to be regular, put the person in the recovery position (select Unconsciousness). Then dial 911.