memory loss; balance issues; sickly; lethargic; emotional problems; tired; a lot of irregular heart beats, Every 6 pulses, it would stop and restart; bad reaction after the second shot; bounding heart beats, like it would come out of my chest, heart started racing; feared for my life; This spontaneous case was reported by a consumer and describes the occurrence of ARRHYTHMIA (a lot of irregular heart beats, Every 6 pulses, it would stop and restart), VACCINATION COMPLICATION (bad reaction after the second shot), PALPITATIONS (bounding heart beats, like it would come out of my chest, heart started racing), FEAR (feared for my life) and AMNESIA (memory loss) in an 80-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 20-Aug-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 17-Sep-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 17-Sep-2021, the patient experienced ARRHYTHMIA (a lot of irregular heart beats, Every 6 pulses, it would stop and restart), VACCINATION COMPLICATION (bad reaction after the second shot), PALPITATIONS (bounding heart beats, like it would come out of my chest, heart started racing) and FEAR (feared for my life). On an unknown date, the patient experienced AMNESIA (memory loss), BALANCE DISORDER (balance issues), ILLNESS (sickly), LETHARGY (lethargic), EMOTIONAL DISORDER (emotional problems) and FATIGUE (tired). At the time of the report, ARRHYTHMIA (a lot of irregular heart beats, Every 6 pulses, it would stop and restart), VACCINATION COMPLICATION (bad reaction after the second shot), PALPITATIONS (bounding heart beats, like it would come out of my chest, heart started racing), FEAR (feared for my life), AMNESIA (memory loss), BALANCE DISORDER (balance issues), ILLNESS (sickly), LETHARGY (lethargic) and EMOTIONAL DISORDER (emotional problems) outcome was unknown and FATIGUE (tired) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 28-Sep-2021, Cardiac stress test: normal (normal) his cardiologist said he was looking good. On 28-Sep-2021, Electrocardiogram: abnormal (abnormal) since that time that shows a little change, but not serious enough to put in a pacemaker..     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   No concomitant medication information provided by the reporter. No treatment information provided Patient had a bad reaction after the second dose but did not go to the hospital. The night of the second shot on 17Sep2021, he started having a lot of irregular heart beats. Every 6 pulses, would stop and restart. He could count them and feel them. Then he would have bounding heart beats, like that would come out of his chest. Then his heart started racing. He was up all night and feared for his life and also had some memory loss and some balance issues. He has been sickly ever since that time, but he has been in very good health for his age. Since then, he was still tired and lethargic and has emotional problems going on with his family.  It was reported that patient had  two EKGs (one of them was on 28Sep2021)  but not serious enough to put in a pacemaker.   Patient had a stress test prior to vaccination and his cardiologist said he was looking good   Patient also had an ultrasound last week on 13Oct2021 but he doesn't have the results yet.  Patient states he was even hesitant to get vaccinated.   Company Comment: This case concerns an 80-year-old, male patient with no relevant medical history reported, who experienced the unexpected event of arrhythmia. The events occurred the same day after the second dose of mRNA-1273. The rechallenge was not applicable since the event happened after the second dose. The benefit-risk relationship of mRNA-1273 in not affected by this report. Event seriousness was downgrade due the patient did not seek medical attention, and there Is no information in the Agency referring hospitalization or any information that was medically significant. Further information was requested.   This case was linked to MOD-2021-361000 (Patient Link).; Sender's Comments: This case concerns an 80-year-old, male patient with no relevant medical history reported, who experienced the unexpected event of arrhythmia. The events occurred the same day after the second dose of mRNA-1273. The rechallenge was not applicable since the event happened after the second dose. The benefit-risk relationship of mRNA-1273 in not affected by this report. Event seriousness was downgrade due the patient did not seek medical attention, and there Is no information in the Agency referring hospitalization or any information that was medically significant. Further information was requested.