How long do the signs of a heart attack last?

Heart attack symptoms like chest pain, shortness of breath, nausea, weakness and cold sweats can last as short as 15 minutes or be staggered over a couple days if untreated. Some people have such mild symptoms that they never realize they had a heart attack until they had an electrocardiogram or echocardiogram that shows heart damage. On the other hand, if a person with sudden formation of a blood clot in a coronary artery that causes a heart attack gets immediate treatment that opens the artery, he or she may be left with no signs of a heart attack.