Diagnosed with Covid-19 in 2022; afib/I had an irregular heart beat; covid 19; This spontaneous case was reported by a patient and describes the occurrence of ATRIAL FIBRILLATION (afib/I had an irregular heart beat) in a 67-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 022C21A, 007B21A and 016M20A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Stroke in 2017. Previously administered products included for Product used for unknown indication: Influenza. Past adverse reactions to the above products included No adverse event with Influenza. Concurrent medical conditions included Sinus disorder (Sinus Allergy). Concomitant products included APIXABAN (ELIQUIS) for Sinus disorder.   On 04-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 01-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 20-Oct-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In 2022, the patient experienced COVID-19 (covid 19). On 10-Jan-2023,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced ATRIAL FIBRILLATION (afib/I had an irregular heart beat) (seriousness criterion medically significant). On an unknown date, the patient experienced VACCINATION FAILURE (Diagnosed with Covid-19 in 2022). At the time of the report, ATRIAL FIBRILLATION (afib/I had an irregular heart beat), COVID-19 (covid 19) and VACCINATION FAILURE (Diagnosed with Covid-19 in 2022) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Heart rate: irregular.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   Patient received other vaccines in the 4 weeks prior to COVID-19 vaccine.  Patient received Moderna vaccines and was diagnosed with AFIB on 10-Jan-2023, which he never had before. The patient mentioned that he had a stroke in 2017 and is checked every year, and during that exam (some type of gram where they put stuff on person) it showed that patent had an irregular heartbeat. Patient also mentioned that he was diagnosed with COVID in 2022, no hospitalizations. Treatment medication was not reported.  Company Comment: This spontaneous case report concerns a 67-year-old male patient with no relevant medical history provided, who experienced serious (medically significant) unexpected event of special interest - Atrial fibrillation, as well as non serious unexpected event of COVID-19. The event of Atrial fibrillation approximately 1 year and 3 months after the patient had received the most recent (third dose of the mRNA-1273 vaccine). It was stated that the patient had irregular hear beat during regular doctor's visit due to previous Stroke and he was diagnosed with atrial fibrillation. The patient developed COVID-19 on an unspecified date during 2022 and all there vaccine were administered in 2021. It was confirmed that the patient was not hospitalized due to COVID-19. The outcome of both events remained unknown and no additional details regarding clinical course of the events were provided. Vaccination failure was also considered in this specific case, having in mind that the patient developed COVID-19 after he received first two doses of the vaccine in accordance with proposed timeliness between doses. Taking into consideration that the event of Atrial fibrillation occurred nearly 1 year and 3 months following the third vaccination, due to temporal implausibility, the causality for this event is assessed as not related to the mRNA-1273 vaccine. The patient's elderly age remains a confounder for Atrial fibrillation. No further details were available for medical assessment. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case report concerns a 67-year-old male patient with no relevant medical history provided, who experienced serious (medically significant) unexpected event of special interest - Atrial fibrillation, as well as non serious unexpected event of COVID-19. The event of Atrial fibrillation approximately 1 year and 3 months after the patient had received the most recent (third dose of the mRNA-1273 vaccine). It was stated that the patient had irregular hear beat during regular doctor's visit due to previous Stroke and he was diagnosed with atrial fibrillation. The patient developed COVID-19 on an unspecified date during 2022 and all there vaccine were administered in 2021. It was confirmed that the patient was not hospitalized due to COVID-19. The outcome of both events remained unknown and no additional details regarding clinical course of the events were provided. Vaccination failure was also considered in this specific case, having in mind that the patient developed COVID-19 after he received first two doses of the vaccine in accordance with proposed timeliness between doses. Taking into consideration that the event of Atrial fibrillation occurred nearly 1 year and 3 months following the third vaccination, due to temporal implausibility, the causality for this event is assessed as not related to the mRNA-1273 vaccine. The patient's elderly age remains a confounder for Atrial fibrillation. No further details were available for medical assessment. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.