Patient's blood pressure was 64/55. Later, patients blood pressure was still pretty low, it was low for 2 hours. The following day, patient had low blood pressure.; Dizziness; Early Friday morning, patient had one bout of diarrhea.; Patients hands were ice cold and he was weak and drained.; Patients hands were ice cold and he was weak and drained.; Patients hands were ice cold and he was weak and drained.; Patient went into A-Fib. Patient's heart rate was jumping from being in the 80s to 90s to 70s, to above 100.; Patient went into A-Fib. Patient's heart rate was jumping from being in the 80s to 90s to 70s, to above 100.; The next day after patient got the first dose of the covid vaccine, he had a little bit of fatigue.; This is a spontaneous report from a contactable consumer (patient's wife). A 71-years-old male patient received bnt162b2 (BNT162B2), via an unspecified route of administration, administered in Arm Left on 24Mar2021 16:00 (Batch/Lot Number: EN6207; Expiration Date: 06Jun2021) as SINGLE DOSE for covid-19 immunisation. Medical history included liver transplant, Patient's liver transplant was 6 years ago. A-Fib from an unknown date. In Feb2020 when covid first came out, patient became ill and was hospitalized for sepsis and double pneumonia. Patient's A-Fib lasted 7 days, he was in an excellent hospital in (Name). Patients heart rate was up above the 170s. The hospital could not manage patients A-Fib because he was so sick. It was not Covid, it was stress. Reporter believes that patients sister has A-Fib. There were no concomitant medications. No history of all previous immunization with the Pfizer vaccine. Additional Vaccines Administered on Same Date of the Pfizer Suspect was None. Prior Vaccinations (within 4 weeks) was None. Patient received a flu vaccine way back in Aug2020. AE(s) following prior vaccinations was Not provided. It was reported that the patient received the first dose of the Pfizer of the vaccine was on 24Mar2021, Wednesday, at 4pm. On Thursday, usual fatigue, that people get, Friday morning, diarrhea 1 bout, and dizziness, gave him water, HR erratic 80, 90 to 70 into 100, which as like AFib, BP went to 64/55, put in in w/c had him lay down, hand cold, weak, drain. He drank electrolyte water. started to take BP and HR and Oxygen level, his Blood pressure was 64/55, She called PCP, the nurse got on the phone and asked questions, and monitor what had happened, monitored Heart rate until 20 minutes it became regulated, in the 90s and staying in the 90s. If his heart rate goes above 110 call me back. continued to do the water thing, did not call her back, things started to normalize, BP normalized in 2 hours and heart rate about the same. The following day, Saturday, he had pressure low but not as low, again just watched and pushed fluids, and got better each day, fatigue got better that Saturday. No other incident following incident. Reporter called yesterday several people, cardiologist, transplant coordinator, PCP again to get advise and direction. She wanted to know whether this was an allergic reaction, even though it happened later, could he get the second shot, could it be worse following the second shot. The reporter was advised that their doctor/healthcare provider is in the best position to assess and advise as their doctor/healthcare provider was most familiar with the medical condition, clinical history, how the treatment had been conducted and any relevant information to the specific case. It was stated that, the patient took Pfizer covid vaccine (Verbatim) to get whatever protection he can from the virus. Patient is a liver transplant patient and (Name) wanted him to get the covid vaccine. The next day after patient got the first dose of the Pfizer covid vaccine, he had a little bit of fatigue. Early Friday morning, he woke up patient had one bout of diarrhea. Then patient went into A-Fib. Patient's heart rate was jumping from being in the 80s to 90s to 70s, to above 100, jumping all around. Patient's blood pressure was 64/55. The reason that reporter thought to take patient's blood pressure is because he became dizzy. As soon as patient got dizzy, reporter had him start drinking electrolyte water, and he lay down in bed. Patients hands were ice cold and he was weak and drained. Reporter called patient's doctors office, and talked to the nurse. With the nurse on the phone, reporter and nurse continued to monitor patients heart rate and blood pressure. The highest that patients heart rate got was 101. The nurse believed that patient was in A-Fib. Maybe after 15 minutes of patient drinking cold water, things started normalize a bit. Patient's heart rate was in the 90s at least it was fluctuating within the 90s. Later, patients blood pressure was still pretty low, it was low for 2 hours. The following day, patient also had low blood pressure. The patient continued to drink cold water, and the reporter was monitoring him. The patient did not go into A-Fib again the next day. Reporter has called several people. Reporter has called transplant people, and patients primary care physician. Reporter was asking them questions about the Pfizer covid vaccine. Reporter asked them if they thought it was an allergic reaction. Reporter asked them if it could happen again with the second dose of the Pfizer covid vaccine. Reporter asked them if they think that patient should receive the second dose of the Pfizer covid vaccine in a clinical setting. Patient received first dose of the Pfizer covid vaccine at a (Name). Reporter asked them if they think that patient should be monitored for a longer time. Reporter asked them if patient could get worse after the second dose of the Pfizer covid vaccine. Reporter was told many different things by all of them. The doctor from would not recommend patient to get the second dose of the Pfizer covid vaccine, but the Doctor also would not recommend for patient to not get the second dose of the Pfizer covid vaccine. The doctor would not say either way, he would only say that he would like for the patient to be vaccinated. The doctor also said that he did not know if it was an allergic reaction, because he was not there to see patient. Patients primary care doctor told reporter that the second dose of the Pfizer covid vaccine is just a needle in his arm, patient just had side effects and that patient should go on and get the second dose of the Pfizer covid vaccine. Primary care doctor told reporter that he did not think it made a difference if patient received the second dose of the Pfizer covid vaccine in a clinical setting. The doctor told reporter that it would be smart for patient to receive second dose of Pfizer covid vaccine at a clinic or hospital setting or whatever. Reporter states that they are looking for some direction. Reporter knows that patient is doing a study with transplant patients. Doctor claimed that transplant patients have all done well with the first dose of the covid vaccine, but only 17% of people got an immune response from the first shot. Patient is hoping for better rates for the second dose of the covid vaccine. Reporter does not know if they are willing to risk patient receiving the second dose of the covid vaccine with patients A-Fib. Reporter states that regardless of what people think of A-Fib, A-Fib increases the risk of a stroke times five. Reporter does not want to purposely put patient into A-Fib. In Feb2020 when covid first came out, patient became ill and was hospitalized for sepsis and double pneumonia. Patient's A-Fib lasted 7 days, he was in an excellent hospital. Patients heart rate was up above the 170s. The hospital could not manage patients A-Fib because he was so sick. It was not Covid, it was stress. Reporter has memories of that, and reporter does not want that to happen again. The next day after patient got the first dose of the Pfizer covid vaccine, he had a little bit of fatigue: Patient did not go to church on Sunday. Patient started feeling better on Saturday, 27Mar2021. Early Friday morning, patient had one bout of diarrhea: Reporter clarifies that patient experienced diarrhea and got dizziness. Reporter knew then that she had to get patient to drink water. Reporter thought that patient might be dehydrated. Patient went into A-Fib. Patient's heart rate was jumping from being in the 80s to 90s to 70s, to above 100: A-Fib started the morning of 26Mar2021. It was resolved completely by the same evening, about supper time. After the A-Fib started, patients heart got more stable after about 20 minutes. Reporter then hung up with the nurse from patients primary care physicians office. Patients heart rate continued to be erratic until supper time, but it was not bad. Patient's blood pressure was 64/55. Later, patients blood pressure was still pretty low, it was low for 2 hours. The following day, patient had low blood pressure: Reporter checks patients blood pressure in the mornings. Patients blood pressure is now back to normal. Patients low blood pressure has resolved. It continued a bit on Saturday, 27Mar2021. It resolved on Saturday evening. Reporter is still having patient push fluids. Patient is still currently drinking a lot of fluids with electrolytes. AE(s) did not require a visit to Emergency Room/Physician Office. Outcome of the event atrial fibrillation, heart rate increased, Dizziness, diarrhoea was recovered on 26Mar2021, blood pressure decreased, fatigue was recovered on 27Mar2021, other events was unknown.