Tachycardia/her heart rate at 11:00PM last night was at around 100/ she checked her pulse it was 115; she was not feeling right, so she took the day off from work today; Lightheadedness; wobbly; she felt weak; This is a spontaneous report from a contactable nurse (patient). A 50-year-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE; Lot Number: EL1284, expiration date: Apr2021), via an unspecified route of administration at right deltoid on 29Dec2020 17:45 at a single dose for Covid-19 immunization. Medical history included asthma from 2003 and ongoing, tachycardia and major surgery. Concomitant medication included maintenance inhaler (unspecified) for asthma. Patient was officially diagnosed with asthma in 2003. She said her asthma was controlled, and she takes a maintenance inhaler every day. She said she has been taking the same maintenance inhaler since she was first diagnosed with the asthma. She said she rarely uses a rescue inhaler. Reported she was prescribed the Metoprolol Tartrate 25mg for her tachycardia that she had after her major surgery, but she did not take the full 25mg dose during that time. She said she hasn't had taken the Metoprolol Tartrate 25mg in almost a year, clarifying it was last Jan2020 that she used the Metoprolol Tartrate. The patient previously received a flu shot in Oct2020, and felt rundown for a day afterwards, but that she always does after she receives a flu shot. She said she had no heart issues after receiving the flu shot in Oct2020. The patient who is a registered nurse reported she received the COVID-19 vaccine last night at work, on 29Dec2020, at 5:45PM, and had experienced some tachycardia after receiving the vaccine. Reported the COVID-19 Vaccine was offered through her employer. She said the COVID-19 vaccine was optional and offered to all employees if they work at the hospital. She experienced the tachycardia at 11:00 PM last night, 29Dec2020. She said her normal resting heart rate is between the high 60s to low 70s. She said her heart rate at 11:00PM last night was at around 100, clarifying she was not running a fever at that time. She stated after she received the COVID-19 vaccine, she was not feeling right, so she took the day off from work today, and slept in. She said when she woke up this morning (in Dec2020), she still didn't feel right, saying she felt weak and wobbly, and when she checked her pulse it was 115. She said she does have a past history of tachycardia. She said a year ago she had major surgery, and she had tachycardia after the major surgery. She said the tachycardia eventually went away, but she did have to see a cardiologist and take a beta blocker. She said she took a tiny dose of the beta blocker this morning, and called the cardiologist to let him know what was going on. She said she has not heard back from the cardiologist yet. She said the tachycardia went away once she took the beta blocker this morning. She said she took the beta blocker because her heart rate was going higher, and higher. She said she didn't want to end up like last year after her major surgery with a heart rate in the 170s. She said the tachycardia she was experiencing after receiving the COVID-19 Vaccine was not normal for her. She said once she got over the major surgery last year, her heart rate was fine. Reported her employer was making employees wait around for 15 minutes after the employees received the COVID-19 Vaccine to make sure no one had a major reaction to the COVID-19 Vaccine. She said after she received the COVID-19 Vaccine, she waited around longer than the 15 minutes. She said she felt weird after she received the COVID-19 Vaccine and thought maybe she was experiencing anxiety. She said she was lightheaded on 29Dec2020 after she received the COVID-19 Vaccine and completed a report right then on the website. She said the website is for reporting adverse events, and she was sent a website link to complete the adverse event reporting. She said she signed into the website link while she was still at the hospital. She said one of the website's first questions asked was how she was feeling. She said the question made her wonder if her lightheadedness was due to her heart rate being up because she becomes lightheaded when that happens. She clarified she reported only the lightheadedness on the website, and not the tachycardia. She said her lightheadedness got better and she was fine, and then at 11:00PM the tachycardia hit her like a switch. Reported this morning she felt fine, and then all of sudden she wasn't fine. Tachycardia Treatment: Reported she took a 8.5mg dose, or one quarter of a 25mg tablet (as provided by the reporter) of the beta blocker Metoprolol Tartrate 25mg tablet this morning and called her cardiologist to let him know. She said she split the Metoprolol Tartrate 25mg tablet this morning, and only took a quarter of the 25mg tablet (reported as a 8.5mg dose by the reporter). Reported she believes 100% that her tachycardia was caused by the COVID-19 Vaccine, saying she has been fine up until receiving the COVID-19 Vaccine. She said she got the COVID-19 Vaccine because she was afraid of getting the COVID-19 Virus with her asthma. She said she has no other preexisting conditions besides the asthma. Reported she is not going to get the second COVID-19 Vaccine dose. She said it was scary when her heart rate shot up out of nowhere. She said the COVID-19 Vaccine is the only thing different she has done. She said before the COVID-19 Vaccine, she was completely fine. Patient asked if the Pfizer DSU agent had heard of anyone else who has experienced tachycardia after receiving the COVID-19 Vaccine. The outcome of the event tachycardia was recovered in Dec2020, event lightheadedness was recovering and unknown for the other events. The reporter assessed the event 'tachycardia' as Serious (Medically Significant).; Sender's Comments: Based on the close temporal relationship, the association between the event tachycardia with BNT162b2 can not be fully excluded. The medical history of tachycardia and asthma medication may be contributory as well.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.