Had a. fib while in the ER; Blood clot between the two lower chambers of her heart; Feet and ankles looked blistered/bubbly; She was in enough pain; everything was just going through her  and she had to start wearing Pull Ups; she had also lost 60 pounds; Top half of heart isn't working/Heart is pumping 10-15%; Top half of heart only flutters.; This spontaneous case was reported by a consumer and describes the occurrence of ATRIAL FIBRILLATION (Had a. fib while in the ER), INTRACARDIAC THROMBUS (Blood clot between the two lower chambers of her heart), BLISTER (Feet and ankles looked blistered/bubbly), PAIN (She was in enough pain), CARDIAC DYSFUNCTION (Top half of heart isn't working/Heart is pumping 10-15%) and CARDIAC FLUTTER (Top half of heart only flutters.) in a 65-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 028A21A and 029L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Defibrillator/pacemaker insertion (Patient had first defibrillator placed in 2007 and she is on her third defibrillator now.) in 2007. Concurrent medical conditions included Cardiomyopathy (she had a weak heart muscle.).   On 01-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 29-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 01-Jun-2021, the patient experienced ATRIAL FIBRILLATION (Had a. fib while in the ER) (seriousness criteria hospitalization, medically significant and life threatening), INTRACARDIAC THROMBUS (Blood clot between the two lower chambers of her heart) (seriousness criteria hospitalization and medically significant), BLISTER (Feet and ankles looked blistered/bubbly) (seriousness criterion hospitalization) and PAIN (She was in enough pain) (seriousness criterion hospitalization). In June 2021, the patient experienced CARDIAC DYSFUNCTION (Top half of heart isn't working/Heart is pumping 10-15%) (seriousness criterion medically significant) and CARDIAC FLUTTER (Top half of heart only flutters.) (seriousness criterion medically significant). On an unknown date, the patient experienced WEIGHT FLUCTUATION (she had also lost 60 pounds) and ANAL INCONTINENCE (everything was just going through her  and she had to start wearing Pull Ups). The patient was hospitalized from 01-Jun-2021 to 06-Jun-2021 due to ATRIAL FIBRILLATION, BLISTER, INTRACARDIAC THROMBUS and PAIN. The patient was treated with APIXABAN (ELIQUIS) for Adverse event, at an unspecified dose and frequency. At the time of the report, ATRIAL FIBRILLATION (Had a. fib while in the ER), INTRACARDIAC THROMBUS (Blood clot between the two lower chambers of her heart), BLISTER (Feet and ankles looked blistered/bubbly), PAIN (She was in enough pain), CARDIAC DYSFUNCTION (Top half of heart isn't working/Heart is pumping 10-15%), CARDIAC FLUTTER (Top half of heart only flutters.), WEIGHT FLUCTUATION (she had also lost 60 pounds) and ANAL INCONTINENCE (everything was just going through her  and she had to start wearing Pull Ups) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Ejection fraction: 10-15% (Low) Heart pumping -10-15 percent.. On an unknown date, Weight: decreased (Low) Lost 60 pounds..         No concomitant medication was reported.  Patient's feet and legs began to swell the first or second week of April.  They continued to swell and on 01-JUN-2021 or 02-JUN-2021. she was in pain that she went to the ER.  A Code blue was called for her and the doctors gave her IVs with the medicine that they use when they inject it straight into the heart. She was admitted to the hospital for 6 days. when she was released from the hospital, she was sent home on home health care. She was in home care. is now on a medicine for the heart rhythm, a blood thinner and Eliquis  Company comment : This case concerns a 65-year-old, female patient with relevant medical history of Cardiomyopathy, who experienced the unexpected serious AESI events of atrial fibrillation, intracardiac thrombus, cardiac dysfunction, and cardiac flutter, and the unexpected serious events of blister, and pain. The events occurred approximately 2 months after the second dose of mRNA-1273 Moderna vaccine. The rechallenge was not applicable as the outcome of the events is unknown. The medical history of Cardiomyopathy (with defibrillator required) could be a confounding factor for the events. The benefit-risk relationship of mRNA-1273 Moderna vaccine is not affected by this report.; Sender's Comments: This case concerns a 65-year-old, female patient with relevant medical history of Cardiomyopathy, who experienced the unexpected serious AESI events of atrial fibrillation, intracardiac thrombus, cardiac dysfunction, and cardiac flutter, and the unexpected serious events of blister, and pain. The events occurred approximately 2 months after the second dose of mRNA-1273 Moderna vaccine. The rechallenge was not applicable as the outcome of the events is unknown. The medical history of Cardiomyopathy (with defibrillator required) could be a confounding factor for the events. The benefit-risk relationship of mRNA-1273 Moderna vaccine is not affected by this report.