Heart Beats Audibly And Fast On Resting, High Pulse Rate, Difficulty In Sound Sleep. Sign Of Perimenopause?

Hello, I am a 49 year old female of normal weight, no health problems, with regular menses. I quit smoking 3 months ago after 32 years. My annual checkup and tests are all normal, including BP , blood sugar , TSH , etc. I exercise regularly - yoga and gym on alternate days. Since the last 10 days, whenever I am at rest (sitting or lying down), I can feel my heart beat very audibly and fast, accompanied by a sensation in my chest and stomach similar to a panic or anxiety attack. I do not actually feel anxious or panicked, just the fluttering sensation and the loud heart beats. When I measure my pulse, it is marginally higher than my normal which is usually between 75 and 85 bpm. The frequency has increased such that it prevents me from falling asleep at night. The more I try to relax the more frequent are the palpitations. They do not bother me when I am busy or physically active. I am constantly tired because of lack of adequate sleep. Is this a part of perimenopause? Thanks in advance... YB