I have been having perimenopausal symptoms for over 14 years, I am now 53. I have the hot flashes, irregular heart beat, anxiety attack, oh, there are so many symptoms.
I take bio-identical estrogen and progesterone, and they really help, you need a doctor to prescribe them and a compounding pharmacy to make them. You can purchase a bio-identical progesterone at a health food store, but, I prefer the ones that are made and prescribed professionally. They are completely safe too, no side effects.
There are two good books to read about menopause and perimenopause. One is called, "What your doctor may not tell you about menopause" and the other is "What your doctor may not tell you about perimenopause" both are written by Dr John Lee, they are a wealth of info, I highly recommend them to all women.
Yes, I am in perimenopause and have racing heart, hot flashes, shakes and tremors along with insomnia.
What has helped me-
I had heart checked out and am on very low dose beta blocker ( atenolol)
I take bioidentical hormones to help insomnia
And if I drink a glass of soy milk daily my hot flashes are GREATLY diminished. It took about a month before I notice a difference.
Do get a cardiac workup , hormones checked and thyroid checked too.
Good luck!