This was one of my first symptoms, starting in 2006. The holter monitor displayed them, but the doctor said they were beneign and not to worry and rx xanax. The endocrinologist suggested beta blockers for what he said was perimenopause (I was 44). Other symptoms being: hot flashes, chills, myalgia, migrating arthralgia, headaches, plantar fasciitis, rage, anxiety attacks, suicidal ideation, derealization, brain fog, short term memory loss.
After much googling I decided that I would treat my "perimenopause" with bioidentical progesterone cream. I started out with a fairly low dose and after suffering some estrogen dominance issues my symptoms felt better. Now I feel pretty good with a dose of about 150 mg per day. Most doctors say that is too much, and that I need to cycle, but most of my symptoms have resolved, and they return when I decrease the dosage. The wonky heart beat was the first symptom to recover. 20 minutes after applying progesterone I could feel it return from that "too fast, I must be getting sick" feeling, and the night time pounding stopped as well. It also resolved the "flu-like" symptoms and rage/anxiety/derealization.
Gestational attenuation of Lyme arthritis is mediated by progesterone and IL-4 in a mouse model:
Progesterone: therapeutic opportunities for neuroprotection and myelin repair
I will be introducing myself on the forum shortly, but felt I had to reply to this question.