04/09, 1:30AM, Got up to go to the bathroom. Got back in bed and my heart started pounding fast. After about 30 minutes of breathing/relaxation exercises, my heartbeat lowers but is still high. I went downstairs, thinking my BP had gone haywire, and got my blood pressure cuff. BP 132/77, 82 BPM. My normal resting BPM is 60. Scared me a lot. Fast forward to 2/20/2023. I'm walking to the kitchen at about 4:30pm, and my heart starts to race again. I had on my Apple watch and immediately did an EKG. EKG is normal but BPM is 132! About 30 minutes later it was at 80 BPM. The whole time it just felt like it was beating hard. Even when I'm out exercising it's more like 90. 132 is not normal!  Apple suggests I contact my doctor, which I did, via doctor portal on line. Interaction below. Heart problems, other than high blood pressure, do not run in my family. Until the vaccination, I had not ever had anything like this. Now, it's happened twice, and I'm on edge wondering when it's going to happen again and if it will be fatal.  Doctor's Response:       Thank you for your message.  There could be so many reasons of having elevation in the heart rate.  Sometime change in hemoglobin, electrolyte abnormality, thyroid problems can cause heart rate to go up.  If your symptoms persist we can start with a lab work first and depending on the nature of the symptoms symptom we have to put heart monitor on as well.  If you continue to have symptoms I would advise you to come to the clinic so we can discuss further in order more testing depending on your symptoms.  We will make sure you keep yourself well-hydrated as dehydration can trigger that as well. ---------------------  From:  Sent: 02/20/2023 02:57 p.m.  Subject: FW: Non-Urgent Medical or Treatment Question  It's a little unsettling to have your heart pounding like for no clear reason. I guess my bigger question is if it happens again, what is the best thing to do? Thanks --------------------- From:   Sent: 02/17/2023 10:19 a.m. MST Subject: Non-Urgent Medical or Treatment Question Thank you for your message. It has been successfully sent to the appropriate care team. Hi, Last April I had my second COVID booster shot. Three days later, at around 1:00am after I went to the bathroom, I was laying in bed and my heart started beating fast and hard. I tried to relaxation breathing, listening to calming music, but without results. About a half hour later I was thinking maybe I should go check my blood pressure. It was 118/75 and the heart rate at that time was 80. I went back to bed and by morning things were normal.  I wasn't too concerned at the time, I just figured it was a random side effect. It had never happened to me before and likely wouldn't again. Yesterday, around 4:30pm, I was walking through my house and without any precipitating event that involved any exertion, my heart starts beating fast and pounding. I was just walking. This time I had my iWatch on and did an EKG immediately. Nothing unusual in that but it showed my heart rate at 136. It was in the 80s about 1/2 hour later but still felt like a harder than usual beat. When I did my weekly Friday evening BP check the results were 125/75 with a heart 64. Now that I've had two episodes of this overly fast and pounding heartbeat, I'm starting to wonder if there's something I should have checked out? Thanks.