Atrial fibrillation; High blood pressure; Feel slightly better but still not feeling good; Could not get out of bed; High rate heart beat; 6 hours after receiving the booster notice 2 or 3 nodes underneath the arm started to swelling and still have them; Arm really hurt/ Hurt to even touch my skin; Can not close the arm due the nodes are still underneath there and hurt; Like flu symptoms; Chills; This spontaneous case was reported by a consumer and describes the occurrence of ATRIAL FIBRILLATION (Atrial fibrillation) in a 64-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 039F21A, 028A21A and 013A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No medical history was reported.  Concomitant products included LOSARTAN for an unknown indication.   On 02-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 30-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 08-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to .25 milliliter. In 2021, the patient experienced INFLUENZA LIKE ILLNESS (Like flu symptoms) and CHILLS (Chills). On 08-Nov-2021, the patient experienced VACCINATION SITE PAIN (Arm really hurt/ Hurt to even touch my skin). 08-Nov-2021, the patient experienced HEART RATE INCREASED (High rate heart beat) and LYMPHADENOPATHY (6 hours after receiving the booster notice 2 or 3 nodes underneath the arm started to swelling and still have them). On 09-Nov-2021, the patient experienced DYSSTASIA (Could not get out of bed). On 10-Nov-2021, the patient experienced FEELING ABNORMAL (Feel slightly better but still not feeling good). In November 2021, the patient experienced AXILLARY PAIN (Can not close the arm due the nodes are still underneath there and hurt). On an unknown date, the patient experienced ATRIAL FIBRILLATION (Atrial fibrillation) (seriousness criterion medically significant) and HYPERTENSION (High blood pressure). On 09-Nov-2021, HEART RATE INCREASED (High rate heart beat) had resolved. At the time of the report, ATRIAL FIBRILLATION (Atrial fibrillation), AXILLARY PAIN (Can not close the arm due the nodes are still underneath there and hurt), INFLUENZA LIKE ILLNESS (Like flu symptoms), HYPERTENSION (High blood pressure) and CHILLS (Chills) outcome was unknown, VACCINATION SITE PAIN (Arm really hurt/ Hurt to even touch my skin) and LYMPHADENOPATHY (6 hours after receiving the booster notice 2 or 3 nodes underneath the arm started to swelling and still have them) had not resolved and DYSSTASIA (Could not get out of bed) and FEELING ABNORMAL (Feel slightly better but still not feeling good) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 10-Nov-2021, Heart rate (60-70): normal (normal) Rate has regularized. On an unknown date, Blood pressure measurement: high (High) High blood pressure. On an unknown date, Heart rate (60-70): 105 (High) 105 (normal rate goes from 60-70).         Concomitant medication includes medication for atrial fibrillation. No treatment information was provided.  The patient was experiencing high rate heart beat (normal rate goes from 60-70) and now tracker states 105. Patient mention talking about this with cardiologist and on 10-Nov-2021 rate has regularized and also mention has diagnosis of high blood pressure and atrial fibrillation. After 6 hours of receiving the booster, patient noticed 2 or 3 nodes underneath the arm had started to swell and still have them, arm really hurt, can not close the arm due the nodes are still underneath there and hurt, patient mention having chills, like flu symptoms. On 09-Nov-2021, patient could not get out of bed.  Company comment: This case concerns a 64-year-old female patient with a relevant medical history of Hypertension and Atrial fibrillation, who experienced the unexpected non serious event of Heart rate increased and other non serious events after mRNA- 1273 Moderna vaccine. The event occurred on the day after the booster dose of mRNA- 1273 vaccine. The rechallenge is not applicable since the event occurred exclusively after the booster dose. Underlying hypertension and atrial fibrillation remain a confounder. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report   This case was linked to MOD-2021-383391 (Patient Link).; Sender's Comments: This case concerns a 64-year-old female patient with a relevant medical history of Hypertension and Atrial fibrillation, who experienced the unexpected non serious event of Heart rate increased and other non serious events after mRNA- 1273 Moderna vaccine. The event occurred on the day after the booster dose of mRNA- 1273 vaccine. The rechallenge is not applicable since the event occurred exclusively after the booster dose. Underlying hypertension and atrial fibrillation remain a confounder. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report