If she laid her arm on it, it was painful on the left side where she got the injection between her left breast and axilla; couldn't go back to sleep; very tired; weak; She had the lump and that was in the lymph node; painful if she put her arm down/painful on the left side/extended underneath the axilla/looked like it was connected to the breast; irregular heart beats; painful if she put her arm down/painful on the left side/extended underneath the axilla/looked like it was connected to the breast; painful if she put her arm down/painful on the left side/extended underneath the axilla/looked like it was connected to the breast; baseball sized lump. It was hard/where she got the injection; It looked like it was connected to the breast because it was so huge.; Fever blister; heart beating so out of rhythm; This is a spontaneous report from a contactable nurse (patient). A 69-year-old female patient received the second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Batch/Lot Number: EN6207), via an unspecified route of administration, administered in arm left on 18Mar2021 at 12:20 (at the age of 69-years-old) as a single dose for COVID-19 immunisation. Medical history included ongoing coeliac disease; hypothyroidism, is diabetic and has irregular heartbeat from an unknown date and unknown if ongoing. Concomitant medications included levothyroxine taken for hypothyroidism; hydrochlorothiazide, olmesartan medoxomil (OLMESARTAN/HCTZ MYLAN) taken for blood pressure measurement; metformin, glipizide and pioglitazone hcl taken for diabetes mellitus; acetylsalicylic acid (ASPIRIN 81) taken for thrombosis; metoprolol taken for heart rate irregular, cyanocobalamin (VIT B12) taken for an unspecified indication, all from an unspecified start date and ongoing; famotidine, rosuvastatin, vitamin d2, vitamin d3 and potassium, all taken for an unspecified indication, start and stop date were not reported. The patient previously received the first dose of BNT162B2 (lot number: EN6198, NDC: 59267-1000-1, expiry: unknown) on 27Feb2021 at 1:40PM for COVID-19 immunisation. The patient got her last shot on 18Mar2021. The first day was fine. She woke up the next morning at three or four with her heart beating so out of rhythm it was crazy. It took almost the whole day. She called her cardiologist and couldn't get into them and she didn't want to go to the ER. She didn't have a way to prove any of that. She also got a baseball sized lump. It was hard. If she laid her arm on it, it was painful on the left side where she got the injection between her left breast and axilla. It extended underneath the axilla. She wasn't able to get in with the cardiologist because she waited to late in the day. She couldn't get off the couch that day because her heart was so out of rhythm. She was very tired and wanted to just lay down. She hates going to the hospital. She doesn't want to go to the hospital. She has a history of irregular heartbeats. She should have gone in and had an EKG. She has pictures of the lump if those are needed. HCP information: Her doctor had said if she had anything like any abnormal heart beats to come in and get an EKG. She also had a fever blister on 22Mar2021 that she hasn't had in years and was asking if this influences her immune system. She had the lump and that was in the lymph node and now a fever blister on the top lip. Heart beating so out of rhythm: it lasted all that day. She took a nap after she talked to the doctor's office and slept for several hours. When she woke up it was kind of back in rhythm, but it was going in and out. It wasn't as frequent as it was prior to nap. Prior to the nap it was almost continuous. It slowed down a lot on the 19Mar2021 and was gone by 20Mar2021. Outcome of event: She has PAC's and PVC's anyway. That is why she follows up with the cardiologist. They haven't been so out of rhythm as they were after the vaccine. She couldn't go back to sleep. She still has them occasionally and that is kind of normal for her. She was weak and tired. Baseball sized lump: it has gone down. She took pictures to show her friends who were all getting the shots. It is gone now. It might have started on 20Mar2021. She woke up with the lump on Saturday. She has recovered completely. Her daughter said she needed to get it checked out. Reporter had heard of a lump on the breast was a side effect. It looked like it was connected to the breast because it was so huge. Seriousness criteria: It was irritating because it was so big. It was painful if she put her arm down. It was like her breast were engorged. Causality: Heart beating so out of rhythm: she hasn't had it that bad, so she thinks it was. She had it a long time ago, maybe once before, but it never lasted that long or took her down like that. She is not the only one that has had the complaint of irregular heartbeats. She put on social media what she experienced and how weak she got. Several friends said that happened to them as well. She doesn't know their history. Reporter declined to do a report on her friends. That was another reason she didn't go to the hospital. She thought it was a normal side effect. She thinks she found on her paperwork about the lump in the lymph nodes. The patient underwent lab tests and procedures which included electrocardiogram: unknown results and heart rate: irregular on an unspecified date. The outcome of the event fever blister was not recovered, while of the rest was unknown. Reporter seriousness for heart beating so out of rhythm was reported as disabling.; Sender's Comments: Based on the information currently available and the plausible temporal relationship, a possible contributory role of suspect product BNT162B2 to the reported events 'heart beating so out of rhythm ', 'baseball sized lump (where she got the injection/It looked like it was connected to the breast because it was so huge)' cannot be completely excluded. 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.