What Causes Severe Heart Palpitations While Resting?

Question: Hi, I am a 59 year old female, in good health and active for most of my life. I have been experiencing heart palpitations almost daily, usually when I lay down, for a couple of years or more. I really haven't been too concerned, but it can be a little alarming. Yesterday and the day before I experienced extreme dizziness and lightheadedness along with nausea and hot flashes followed by fatigue and shakiness. I've experienced this before but not this extreme. The first time (the day before yesterday) I was moving around and active. Yesterday it occurred while I was relaxing, and it was worse, lasting for more than an hour. I don't know if this has anything to do with my heart. I took my blood pressure yesterday and it was normal (125/75) but my heart rate was 59 (my resting heart rate is normally pretty low). I drink about 3 cups of coffee a day, non-smoker (I wear a nicotine patch but haven't smoked in many years), I occasionally have a glass of wine, I'm on HRT, no other medications or supplements. Next week I am having surgery to have breast implants removed and I'm a little concerned about being put under anesthesia. I would like your expert opinion on what my symptoms could be caused from and whether or not undergoing surgery at this time is wise. I have a regular doctor but haven't seen him in 2 years, only my Ob/Gyn. Thank you.