Waking up out of sound sleep w/ heart rate @ 120+bpm

36 yr old female, who has had heart palpitations for over 6 yrs now. I have been taking digoxin .25mg to help control them and 2 baby aspirin daily. I have just started waking out of a SOUND sleep with heart rate in excess of 126 bpm w/ bp146/98 (last night). I will then start shaking. I did goto the ER a few weeks back when my heart rate was 158 bpm and a bp of 198/110, the EMT said I was having an anxiety attack. When I got to the hospital they ran tests and noted that I had no level of digoxin in my blood. While in the ER I fell asleep and my heart rate went up to 160bpm. They gave me a beta blocker and a shot of digoxin and told me I had tachycardia. I went to my cardiologist, she increased my digoxin from .25 to .375 and told me that my potassium level was on the lower end of normal to eat a banana or drink a glass of OJ daily. I had asked her if she thought it was some sort of panic attack (I have no prior panic attacks) with really no response other than lets monitor for the next 3 months. Well it has been 3 weeks now and I have woken up at least 2 times a week w/ the same problem. Last night my heart rate remained over 100bpm for 45 mins (bp at first 146/98 126bpm then went down to 136/88 while heart rate still 112bmp and pounding) then it remained in the 90's for about another 20 minutes. Once my heart rate got down into the 80 bpm range it still just feels like it is going to POUND through my chest. I turn on tv and try to take my mind off of it. Once I fall asleep I remain asleep for the rest of the night. Right now I am stressed about the economy and our personal finances, but I don’t feel that I take it bed with me. So I am hoping a DR could respond and tell me what I can do to keep these episodes to a min and when they do occur what is the BEST thing to do to get my heart rate under control? Please share any natural supplements that may help w/ this. Is this what anxiety is about, or is this heart related? Thank you in advance for your help!

[Cleveland Clinic]

It sounds that you have an SVT but need an event monitor to document the possible type of SVT, so as to plan the ablation procedure needed. This SVT conducts very fast and is not very responsive to beta blockers so I think that you will probably need an EP study with possible ablation to eliminate either dual AV node physiology, atrial focus or an accessory pathway.

[Rob2008]

I sometimes wake up with a pulse of over 160.    But it goes away once I get woke up good.  I was offered an EP study but declined because its' so infrequent