Why I get lightheaded, feels like heart tries to jump out my chest?

[K_G26]

I'm 18 an I keep hearing my heart beat in my right ear when it feels like my hearts fluttery or sometimes feels like it beats out of sync. It happens quite often. Sometimes I'm just laying trying to sleep or I'm at work but it starts with me getting light headed feeling like I'm going to faint. Sometimes get sharp pains in my chest which get worse when I breathe. But it feels like my heart adds an extra beat and it's a strong one that feels like it knocks the air out of me like someone jumped on my chest. It's so uncomfortable and makes me breathless.while it was happening I read my pulse and one minute it was 34 next it was 130 then down to 50.

[Valkryieblade]

One possibility is that your palpitations are triggering an anxiety attack.  The attack could make your chest feel tight as the muscles contract and it can make you feel lightheaded, it would also affect your BP.  I'm not a medical professional but I've experienced similar palpitations to what you describe.  First thing you should do is consult a doctor to rule out rule out more serious things.  Hope that helps.