INFLAMMATORY RESPONSE TO THE VACCINE; VACCINE PROVOKED ARRHYTHMIA; SWOLLEN LYMPH NODES UNDER ARMS; FLU-LIKE SYMPTOMS; This spontaneous report received from a patient (who is a Nurse) concerned a 59 year old female. Initial information received on 25-Aug-2021 was processed with additional information received on 14-Sep-2021. This case was reassessed as serious based upon new information received from patient (nurse) on 14-Sep-2021. The patient's weight was 139 pounds, and height was 62 inches. The patient's past medical history included: two cardiac ablations, and concurrent conditions included: accelerated idioventricular rhythm, shellfish allergy, penicillin allergy, non alcohol user, and non smoker, and other pre-existing medical conditions included: The patient did not have any history of drug abuse or illicit drug use. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 206A21A expiry: 21-SEP-2021) dose was not reported,1 total, administered on 25-AUG-2021 to left arm for prophylactic vaccination. Concomitant medications included metoprolol for vaccine provoked arrhythmia, accelerated idioventricular rhythm, and inflammatory response to the vaccine.  On 25-AUG-2021, twelve hours after the vaccination, the patient experienced flu-like symptoms that were not severe, and resolved in 24-48 hours. On 11-SEP-2021, the patient experienced swollen lymph nodes under arms that went away in a day or two, and this happened multiple times where one swollen lymph node would resolve, and another would become swollen. On 14-SEP-2021, the patient noticed that had some skipped beats and this became more frequent. On 22-SEP-2021, the patient visited cardiologist because symptoms were not going away and the cardiologist suspected that the patient is experiencing an inflammatory response to the vaccine and had Electrocardiogram (NR: not provided) Result not reported and done and metoprolol was increased from 25mg twice a day to 100 mg/day. On 23-SEP-2021,the patient visited to family doctor. On 23-SEP-2021 had blood work done (NR: not provided) including a, basic metabolic panel (NR: not provided), C-reactive protein (NR: not provided), Complete blood count (NR: not provided), and Echocardiogram (NR: not provided), which resulted all normal and was prescribed an anti-inflammatory. The patient stated that symptoms are not getting any better, despite the increased dosage of metoprolol for 1 week. The patient will be following-up with a physician at the end of the week and stated that the vaccine seems to have provoked arrhythmia. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from flu-like symptoms on AUG-2021, and swollen lymph nodes under arms on SEP-2021, and had not recovered from inflammatory response to the vaccine, and vaccine provoked arrhythmia. This report was serious (Other Medically Important Condition).; Sender's Comments: V0 20210956440-COVID-19 VACCINE AD26.COV2.S-vaccine provoked arrhythmia. This event(s) is considered not related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event(s) than the drug. Specifically: MEDICAL HISTORY.