I had racing heart and had a holter monitor and ecg and electrocardiogram test that shows nothing bad but now after 2 years i started experiencing skipped heart beats especially if i'm climbing the stairs, scared to exercise, should i be worried ?

Worry does not help.: What was true 2 yrs ago does not apply now. Your symptoms may be due to simple premature beats. The first step is to get evaluated. If you have premature beats with no underlying heart problem reassurance may be all you need. Avoid coffee, tea, alcohol or other stimulants. If you have a heart problem, it should be evaluated by a cardiologist.