blood pressure dropped really low (80); atrial fibrillation/a-fibrilliation; feels weird in her body; This spontaneous case was reported by a patient family member or friend and describes the occurrence of ATRIAL FIBRILLATION (atrial fibrillation/a-fibrilliation) in a 69-year-old female patient who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient never had COVID positive test or diagnosis. No other vaccines given within 1 month prior to Moderna COVID-19 vaccine.  The patient's past medical history included Pulmonary sarcoidosis, Cutaneous lupus erythematosus and Bypass surgery (She recently had a quadruple bypass surgery 2 months before reporting). Previously administered products included for Drug use for unknown indication: Amiodarone (Patient was given amiodarone and but it was not using that at the moment anymore.). Past adverse reactions to the above products included No adverse event with Amiodarone. Concurrent medical conditions included Penicillin allergy and Asthma.    On 03-Sep-2022, the patient received fourth dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (unknown route) 1 dosage form. On 10-Sep-2022, the patient experienced HYPOTENSION (blood pressure dropped really low (80)). In September 2022, the patient experienced ATRIAL FIBRILLATION (atrial fibrillation/a-fibrilliation) (seriousness criterion medically significant) and FEELING ABNORMAL (feels weird in her body). On 12-Sep-2022, HYPOTENSION (blood pressure dropped really low (80)) had resolved. At the time of the report, ATRIAL FIBRILLATION (atrial fibrillation/a-fibrilliation) had not resolved and FEELING ABNORMAL (feels weird in her body) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 07-Sep-2022, Blood pressure measurement: fine. On 07-Sep-2022, Heart rate: little high and 123 123 beats per minute. On 10-Sep-2022, Blood pressure measurement: blood pressure dropped really low, like in the 80s. It lasted a couple of hours.. On 10-Sep-2022, Heart rate: high. On 12-Sep-2022, Blood pressure measurement: it was happening, but it wasn't happening as long. It lasted a couple minutes but then it stopped..         No concomitant medications were provided.  They went to the emergency room on 07Sep2022, and they found that she was in atrial fibrillation. He knew that one of the symptoms was a fast heart beating.  On Sunday 11Sep2022, she didn't have an episode. On Monday 12Sep2022, it was happening, but it wasn't happening as long. It lasted a couple minutes but then it stopped. He was concerned. Before taking the booster, she was fine. He didn't know if it was caused by the vaccine. Patient took Moderna COVID-19 vaccine dose 1 , dose 2 and 1st booster on an unknown date in 2021 and bivalent booster on 03-Sep-2022.  No treatment medication was provided.  Company comment: This spontaneous case concerns a 69-years-old female patient with relevant history of Bypass surgery (quadruple bypass surgery 2 months ago), who experienced the unexpected, serious (medically significant) event of Atrial fibrillation and other non-serious events that occurred 7 days after the fourth dose of mRNA-1273.222 vaccine in covid-19 vaccination series. It was reported that patient was visited the emergency room and they found that she was in atrial fibrillation and experienced Hypotension and Feeling abnormal. No additional details of Clinical course, Concomitant medication and treatment details were not provided, and the event was resolved. The relevant history of Bypass surgery (quadruple bypass surgery 2 months ago) could be the risk factor for the event. The benefit-risk relationship of the mRNA-1273.222 vaccine is not affected by this report. Events seriousness was assessed as per medical judgement and available information.; Sender's Comments: This spontaneous case concerns a 69-years-old female patient with relevant history of Bypass surgery (quadruple bypass surgery 2 months ago), who experienced the unexpected, serious (medically significant) event of Atrial fibrillation and other non-serious events that occurred 7 days after the fourth dose of mRNA-1273.222 vaccine in covid-19 vaccination series. It was reported that patient was visited the emergency room and they found that she was in atrial fibrillation and experienced Hypotension and Feeling abnormal. No additional details of Clinical course, Concomitant medication and treatment details were not provided, and the event was resolved. The relevant history of Bypass surgery (quadruple bypass surgery 2 months ago) could be the risk factor for the event. The benefit-risk relationship of the mRNA-1273.222 vaccine is not affected by this report. Events seriousness was assessed as per medical judgement and available information.