doctor im 33 unmarried and 55 kgs in weight and height 5 feet i have been diagnosed with asd and was operated for closure of asd and mitral valve repair now my valve is double orifice and other things are normal only the size of valve is reduced to 2 cm.i also suffer from gynaecological prob having severe menses every month ...due to harmonal trtmnt and other trtmnts i gained lot of weight i m an exercise freak and enjoy exercisng but while brisk walking i feel tightness in throat and chest and i have to withdraw exercise..my cardiologist says tht it is not because of heart..i feel that i have some lung abnormality . i feel good after exercising but brisk walking makes me feel heavier in chest and throat ..wht should i do to cure this and exercise