<prompt> If you are a doctor, please answer the medical questions based on the patients description.hi What does it mean... I will to to bed 10pm and sleep through the night maybe get up for the bathroom once or twice. I start work at seven thirty am so I would get up at six thirty. so i got to bed and every morning i wake up and by just opening my eyes and all of a sudden my heart is beating fast, then i will do some breathing and it goes back to normal. what does this mean and what should i do. I had a sleep apnea test and that was fine but i;m wondering if i need to get another.  <response>: Hi, when youre about to wake up, your sympathetic system is most active just before that. thats the reason a person may feel fast beat while waking up. Moreover, in REM sleep your heart rate is faster, and we have Chat Doctor. dont worry. I suggest you take an ECG just to have a baseline. And do yoga and meditation. If its causing you too much trouble, then consult a cardiologist.24 hrs holder or stress test may be advised. 