experiencing extra beat, high rate of beats per second; had a fierce itch for 2 weeks; flutters; having cramps like a Charlie horse in her legs more than normal; harder for her to breath; arms hurt/feet are beginning to hurt; pain is becoming more pronounced, is constant, hurts too bad to exercise, hurts so bad she doesn't want to get out of bed/has a pacemanker/defibrillator and surrounding tissue is sore; not resting well at night because of the pain; hips hurt, shoulders hurt, joint pain; thigh muscles hurt, every muscle hurts; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of ARRHYTHMIA (experiencing extra beat, high rate of beats per second) and CARDIAC FLUTTER (flutters) in a 75-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 020b21a and 014m20a) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included COVID-19, Pacemaker insertion (cardiac) and Implantable defibrillator insertion. Concurrent medical conditions included COPD, Asthma and Thrombosis arm (blood clot in her left arm). Concomitant products included FLUTICASONE PROPIONATE, SALMETEROL XINAFOATE (ADVAIR), UMECLIDINIUM BROMIDE (INCRUSE), SACUBITRIL VALSARTAN SODIUM HYDRATE (ENTRESTO), APIXABAN (ELIQUIS) and LEVOTHYROXINE for an unknown indication.   On 05-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 02-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 02-Apr-2021, the patient experienced MYALGIA (thigh muscles hurt, every muscle hurts). On 09-Apr-2021, the patient experienced MUSCLE SPASMS (having cramps like a Charlie horse in her legs more than normal), DYSPNOEA (harder for her to breath), PAIN IN EXTREMITY (arms hurt/feet are beginning to hurt), PAIN (pain is becoming more pronounced, is constant, hurts too bad to exercise, hurts so bad she doesn't want to get out of bed/has a pacemanker/defibrillator and surrounding tissue is sore) and POOR QUALITY SLEEP (not resting well at night because of the pain). 09-Apr-2021, the patient experienced ARTHRALGIA (hips hurt, shoulders hurt, joint pain). On 30-Jun-2021, the patient experienced CARDIAC FLUTTER (flutters) (seriousness criterion medically significant). On an unknown date, the patient experienced ARRHYTHMIA (experiencing extra beat, high rate of beats per second) (seriousness criterion medically significant) and PRURITUS (had a fierce itch for 2 weeks). The patient was treated with HYDROCODONE for Adverse event, at a dose of 1 dosage form. At the time of the report, ARRHYTHMIA (experiencing extra beat, high rate of beats per second) and CARDIAC FLUTTER (flutters) outcome was unknown and MUSCLE SPASMS (having cramps like a Charlie horse in her legs more than normal), DYSPNOEA (harder for her to breath), PAIN IN EXTREMITY (arms hurt/feet are beginning to hurt), PAIN (pain is becoming more pronounced, is constant, hurts too bad to exercise, hurts so bad she doesn't want to get out of bed/has a pacemanker/defibrillator and surrounding tissue is sore), POOR QUALITY SLEEP (not resting well at night because of the pain), PRURITUS (had a fierce itch for 2 weeks), MYALGIA (thigh muscles hurt, every muscle hurts) and ARTHRALGIA (hips hurt, shoulders hurt, joint pain) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood test: normal (normal) normal. On an unknown date, Computerised tomogram: normal (normal) normal and clear.         Patient reported that within one week she started hurting.She stated every muscle hurts.Her hips, arms, shoulders hurt and now her feet are beginning to hurt.She stated her thigh muscles hurt.She says it was both joint and muscle pain.She was not resting well at night because of the pain. Pain was becoming more pronounced and was constant.She also reported having cramps like a Charlie horse in her legs more than normal.She states it hurts too bad to exercise and some days it hurts so bad she doesn't want to get out of bed.She also reported that it was harder for her to breath since she got the vaccine.Her doctors have run a battery of tests and cannot find anything.She reported her autoimmune test was normal.Doctors have told the patient that everything was fine.She had a pacemaker/defibrillator and stated the surrounding tissue was sore.She had a history of a blood clot in her left arm since the pacemaker/defibrillator implantation, so she doesn't use that arm for medical procedures.She forgot to mention that she had a fierce itch for 2 weeks and the doctors told her she can use antiitch cream.She also reports she took a THC/CBD gummy which worsen her pain.She took a Hydrocodone at a different time and that made her side effects hurt even worse the next morning.She went to a cardiologist and they took a CAT scan and blood work (which came out normal and clear).She also reported that getting out of bed today was a killer.She visited her cardiologist on 30-jun-2021, since then she was experiencing extra beat.She never experienced this before, high rate beat per second.She had a pacemaker.Patient stated that this symptom started immediately after the second dose.She had a follow-up with her cardiologist reading her pacemaker.She claims that she was told that she had flutters this time.  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   This case was linked to MOD-2021-211592, MOD-2021-211687 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 07-Jun-2021: Additional information received on 07-Jun-2021 contain no new information. On 03-Jul-2021: Additional information received on 03-Jul-2021:Additional event of fierce itch was added, laboratory data was added, treatment information was updated and event outcome was updated. On 08-Jul-2021: Additional information received on 08-Jul-2021: Additional event flutters was added.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.