After I got home from my shot I wrote down everything I could think of about my experience in a Google doc and updated it over the course of the next few days. I used dashes to indicate where the bullet points were on my list. - 11:26 am - walked out from getting my shot, sat down, and checked my phone for the time to start the 20 minute clock. - About 4-5 minutes later - Started feeling my heartbeat increase speed, a sense of panic/dread and a feeling that something is wrong that I can't really explain, feeling light headed a little, and some tightness in my chest. My heart was also pounding like it was going to beat its way out of my chest. - For maybe 5ish breaths it felt harder to breathe. Not to get air in, but because of tightness in my chest and the pounding heart. This coincides with the fastest heart beats and starts shortly after my heart starts pounding. - Heart beat feels like it can't physically go any faster or beat anyharder at the peak of it. - The entire thing lasts maybe 10-20 seconds. The peak of it lasts maybe 5 seconds if that. - About 11:40-45 am the same thing happens, but to a lesser extent. I would consider the severity of it about 60-70% of the first episode. Probably lasted about 5 seconds shorter than the first one. - About noon I felt a little tightness around my chest and a slight sense of dread/panic for maybe 20 -30 seconds. This was overall pretty mild compared to the first episode. - Starting about 2:10 pm my heart started beating faster and I experienced a couple of episodes of having difficulty breathing, though none lasted long. This continued for probably an hour or so before calming down before starting up again. The second one probably lasted about 30-45 minutes. - Both of these instances immediately followed walking up stairs. - After this I largely settled into just having a higher heart rate. - After lying down for an hour I timed my heart rate at 116 beats per minute. During my time lying down my heart would settle into beating a little over 100 beats per minutes for 20-45 minutes and then increase closer to 130 beats per minute for a similar duration. - The next day my heart rate was still elevated so I called a nurse practitioner hotline from my insurance and they recommended I get checked out as my symptoms could be a sign of a serious condition. - All other symptoms/reactions from the vaccine were normal ie headache, fever, chills, etc. - When I got my first shot I had a similar but much shorter reaction. - I was driving. I had waited 20 minutes after the shot and left pretty close to 20 minutes after. Got in my car, set up maps, and started driving. I was probably about 20-30 minutes down the road when the symptoms hit. - Started with a weird uneasiness and sense of dread/something is wrong. Got a little light headed. - Heart started beating faster and heavier for about 20 seconds, peaking at a pretty fast and heavy rate. I didn't time it but I'd guess roughly 2-3 beats a second. Felt like it was going to beat its way out of my chest. - Started getting better and I turned around to go to home as soon as I could. By the time I found it I was feeling pretty normal, the whole thing lasted about 20-30 seconds. - Sat for about 20-30 minutes and didn't feel anything. Started driving again. - Had a brief second episode after about 10 minutes of driving, felt the panic/dread come back. Quicked breath and elevated heart rate also came back but to a much lesser extent. Overall it lasted maybe 10-15 seconds and was probably 25-35% of the severity of the first one. I remember the least about this one so my estimation of the overall severity could be off. - No other reaction than normal shot symptoms later that day and the next ie feeling like I had a very mild cold. I didn't report this or follow up on it as I thought I was just anxious about getting my shot and I let it go to my head. After my second shot I experienced nothing like this - everything was normal. For my first shot I got Moderna Lot 041B31A on 04/25/21. It was intramuscular in my left arm. Overall notes: Once these events were over everything else I experienced was comparable to previous vaccines (flu shots, etc.). There was nothing else that caused me concern or had me worried. - When I compare reactions to others I didn't measure how many beats per minute my heart was doing or anything else that could provide hard data. It's an overall approximation that takes into account everything. - I've had plenty of shots in my life and never experienced any of the symptoms I listed above. I was very surprised when the first one happened because I was expecting very mild cold like symptoms the next day if anything. - If I did not list it above I didn't experience it from the shot. I checked the shot site after all shots and there was no itching, swelling, rash, or hives. - In between the episodes noted above I felt completely normal. - For the first two shots my cold symptoms typically lasted about 24 hours, give or take a couple hours before drastically improving. Within 48 hours they were gone.  Feel free to contact me via email, text, or call. You are likely to get a faster response by calling or texting.