ANSWER: Hello and welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Every heart attack causes a drop in the strength of the heart .due to sudden reduction of blood flowing from heart . Body organs including brain get reduced blood supply leading to fatigue . As far as you are concerned ,you need to have coronary angiography , carotid doppler , blood tests (lipids) . You will need to follow your doctors advise (who will )after assessing these reports. Hope I have answered your query. Let me know if I can assist you further.