Waking up disoriented and fast heartbeat?

sounds to me like you may want to see a doctor about that. in my opinion I would say you could use some more sleep to start with and also possibly trying to eat something before you go to bed. I have a similar problem myself. i'll wake up a lot of the times and my vision will become all colorful and blurry, i feel like im gonna faint, and my heart will race. my doctor said it could be low blood pressure and if you eat something at night it could help that. also Supra-ventricular tachycardia is a condition where your heart races and is actually quite dangerous. many people have been diagnosed with this but unless you have been experiencing your heart "fluttering" on other occasions besides when you wake then you more than likely don't have to worry. but my grandma, mama and me all have it and I know the feeling of your heart not calming down. it feels crappy. It can be treated with medication or a very simple surgery though if one was to find they had the disease. Hope this helped and hope you can find some help and your problem gets better. good luck and take care :)