arrhythmia issues; drowning when she was talking; inflammation in a part of her heart; tachycardia 127-130 beats for minute; chest closing; heart pounding strong; This spontaneous case was reported by a consumer and describes the occurrence of ARRHYTHMIA (arrhythmia issues) in a 45-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 014c21a and 039a21a) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 25-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 22-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced ARRHYTHMIA (arrhythmia issues) (seriousness criterion medically significant), SPEECH DISORDER (drowning when she was talking), INFLAMMATION (inflammation in a part of her heart), TACHYCARDIA (tachycardia 127-130 beats for minute), CHEST DISCOMFORT (chest closing) and PALPITATIONS (heart pounding strong). The patient was treated with ATORVASTATIN CALCIUM for Adverse event, at a dose of 10 mg; METOPROLOL for Adverse event, at a dose of 25 mg and ASPIRIN [ACETYLSALICYLIC ACID] for Adverse event, at an unspecified dose and frequency. At the time of the report, ARRHYTHMIA (arrhythmia issues), SPEECH DISORDER (drowning when she was talking), INFLAMMATION (inflammation in a part of her heart), TACHYCARDIA (tachycardia 127-130 beats for minute), CHEST DISCOMFORT (chest closing) and PALPITATIONS (heart pounding strong) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Heart rate: 127-130 beats for minute (High) even with medicine not less than 100..  Concomitant medication was not provided.  The patient started to experience 2 months following vaccination: arrhythmia issues since some months ago, inflammation in a part of her heart, drowning when she is talking, tachycardia 127-130 beats for minute even with medicine not less than 100, chest closing, heart pounding strong. The symptoms are ongoing and getting worse.  Company Comment - This spontaneous case concerns a 45-year-old, female patient with no medical history reported, who experienced the unexpected, serious AESI of arrhythmia and other associated unexpected, non-serious events. The events occurred 2 months after administration of a dose of the Moderna mRNA-1273. The patient sought consult and was prescribed with Atorvastatin calcium 10 mg, Metoprolol ER 25 mg and Aspirin (unspecified dose). She was also referred to a Cardiologist. Based on the reporter, the patient's symptoms had not resolved at the time of the report and are getting worse. The rechallenge was not applicable as no additional dosing will be given. The benefit-risk relationship of the Moderna mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 45-year-old, female patient with no medical history reported, who experienced the unexpected, serious AESI of arrhythmia and other associated unexpected, non-serious events. The events occurred 2 months after administration of a dose of the Moderna mRNA-1273. The patient sought consult and was prescribed with Atorvastatin calcium 10 mg, Metoprolol ER 25 mg and Aspirin (unspecified dose). She was also referred to a Cardiologist. Based on the reporter, the patient's symptoms had not resolved at the time of the report and are getting worse. The rechallenge was not applicable as no additional dosing will be given. The benefit-risk relationship of the Moderna mRNA-1273 is not affected by this report.