From last one year i sometime feel that my heart is beating hard...occassionally it happens...like a certain strong beat which i can feel inside my chest... It creates no problem...no pain.. Nothing...bt why it is happening i donno... I m scared about any kind of heart desease it is... Today i feel it sometimes when i was walking on the street...its like little hard beating once and it happened after and after few seconds... Is it a heart problem...? Plz help