I was just woken up by an irregular heart beat and I m wondering if I should go to the doctor or if it s something more serious. I ve never felt my heart beat so hard or slow before, it was like I was waiting for my heart to start beating again (it lasted for about a minute). I m an otherwise healthy 20 year old female with Postural Orthostatic Tachycardia Syndrome . So I know what the occasional irregular beat will feel like, but this was different since I was sleeping and didn t change position. I ve had EKG s before that have been normal, and an ultra sound that showed a slight mitral valve prolapse with regurgitation, but otherwise have no serious medical conditions… So I guess I m wondering if this sounds like something that could have been brought on a pre existing condition, or if I should be worried?