I have shortness of breath from past 2-3years I feel difficulty While climbing stairs long walk doing excess home chores, After having meal I feel heaviness in chest n I cannot talk, I breath through mouth during tat time, Sometimes my heart beats becomes rapid, Last month I took ecg n chest X-ray both reports were normal , then y do I have these symptoms, I still doubt it is something related to heart plz suggest me if it is a heart problem or not??? Or what could b d causes of this