My heart skips beats???????????

my heart started skipping beats in feb of 2011 and it skipped a beat every time it would beat it done this for 2 weeks nonstop and after and the 2nd day of my heart skipping beats everytime i would move my head the room would spin and i felt dizzy and then after the 2 weeks is slow started to go away it stop in april i went to the hospital in may and my heart wouldnt skip a beat while i was up there and they said that i have heart palpitations and then it still skipped beats and then i told my dad something isnt right then we when to another hospital then they dont a ecg and took pictures of my heart and then i sent me papers on it and i dont really understand or even know for sure what is wrong with me but it said impression =left ventricular ejection fraction function 50% and something else i dont remember but everytime i look it up it will say heart failure i have go to children's hospital july 6th and im 17 years old and i was wondering if that is what is wrong with me and what it is?