Hi There I ve read your query and understanding your concern. See , in young age it s unlikely to have heart disease until unless you smoke heavily or you have very strong cardiac family history. Pain right after smoking doesn t indicate to have heart disease but you can see a physician who can prescribe some routine test like your cholesterol level , heamogram , ECG and Echocardiography to check your heart function. To avoid Heart disease you should avoid smoking. Because the more you smoke the more calcium deposits in areteries and can be reason for heart attack. Hopefully I answered all your queries Good Luck