Atrial fibrillation; This is a spontaneous report from a contactable consumer (patient). A 51-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE), dose 2 at the age of 51-year-old via an unspecified route of administration, administered in left arm on 03May2021 (Lot Number: ER8736) as dose 2, single for COVID-19 immunization. Medical history included COVID-19 from Dec2020 to an unknown date (he "had COVID-19 at the end of Dec2020"), high cholesterol and fasting sugar was high, and it was always high. Concomitant medications include the patient was on other medications (unspecified) but has been on them a long time. The patient was previously vaccinated with the first dose of BNT162B2 (lot number: EP7533) on 12Apr2021 (15:00-15:45) at the age of 51-year-old administered at the right arm for COVID-19 Immunization. The patient also previously had yellow fever, typhoid, and MMR re-boosted because the titers were not high enough to leave country. The patient had both injections and about a month later from the second dose (Jun2021) started to have his heart beat funny. He was only 51 years old and has been monitored and never had any issues. He was diagnosed with AFib on 08Jul2021. He feels he was a little too young for that. He eats right and exercises. He does not know if it was nature or if it came from the vaccine. He has been in the pharmaceutical industry but confirmed he does not work for Pfizer. He understands there may not be enough data, but he would like to know if there have been any other reports of AFib reported. He worked with a company that sold rare disease and cancer drugs. They used to get drugs approved for Phase 1 and 2 trials for 60 patient trial size. He said the cardiologist picked it up. He had to wear heart monitor for 2 weeks. His cardiologist picked it up when he listened to his heart. He put a heart monitor on him for 10 days and got report that he needs to go in for ablation therapy and cut scars in heart to get electrical activity in heart back to normal. He knew he had a little AFib and did not know it was as bad as it was. They just listen to your heart and that was the first time ever when the doctor listened to his heart and after the halter monitor, he told him he was in it all the time and said he had to fix it so he would not have a stroke. They put him on blood thinners. He had a Stress test, EKG, Echocardiogram, all unknown results and related to his going to the cardiologist. He does not know if it was the vaccine or not. All tests were done when he saw him on 08Jul2021. They put the halter monitor on 08Jul2021 for 7-10 days and he put it in the mail and physician called back yesterday and said he was in AFib all the time. The event resulted in physician office visit since he felt like heart was not beating right and made appointment with cardiologist. The patient underwent lab test and procedures which included routine blood work: unknown results, cholesterol: high, fasting sugar: high but it was always high, hemoglobin A1C: under 5, blood glucose: 105, all on an unspecified date. The outcome of the event was not recovered.   No follow-up attempts are needed. No further information is expected.