Had a very bad reaction, so bad that was having heart attack; Chest cold; Thinks she needs to go get her heart checked. She is experiencing enough pain to give someone a Heart Attack.; Tendons are sensitive. I am very sensitive; Flashes of sharp pain/painful/horribly painful like somebody stabbed her/Body aches felt it was terrifying; Muscle spasm from arm to chest; Severe reaction/shot made her feel worse; Knee hurt; Periodic neurologic pain; This spontaneous case was reported by a consumer and describes the occurrence of MYOCARDIAL INFARCTION (Had a very bad reaction, so bad that was having heart attack), LOWER RESPIRATORY TRACT INFECTION (Chest cold) and ANGINA PECTORIS (Thinks she needs to go get her heart checked. She is experiencing enough pain to give someone a Heart Attack.) in a 50-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 048B21A and 038C21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included COVID-19 in January 2021. Family history included Guillain-Barre syndrome.   On 28-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 26-May-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient experienced MYOCARDIAL INFARCTION (Had a very bad reaction, so bad that was having heart attack) (seriousness criterion medically significant), LOWER RESPIRATORY TRACT INFECTION (Chest cold) (seriousness criterion medically significant), ANGINA PECTORIS (Thinks she needs to go get her heart checked. She is experiencing enough pain to give someone a Heart Attack.) (seriousness criterion medically significant), TENDON DISCOMFORT (Tendons are sensitive. I am very sensitive), PAIN (Flashes of sharp pain/painful/horribly painful like somebody stabbed her/Body aches felt it was terrifying), MUSCLE SPASMS (Muscle spasm from arm to chest), VACCINATION COMPLICATION (Severe reaction/shot made her feel worse), ARTHRALGIA (Knee hurt) and NEURALGIA (Periodic neurologic pain). At the time of the report, MYOCARDIAL INFARCTION (Had a very bad reaction, so bad that was having heart attack), LOWER RESPIRATORY TRACT INFECTION (Chest cold), ANGINA PECTORIS (Thinks she needs to go get her heart checked. She is experiencing enough pain to give someone a Heart Attack.), TENDON DISCOMFORT (Tendons are sensitive. I am very sensitive), PAIN (Flashes of sharp pain/painful/horribly painful like somebody stabbed her/Body aches felt it was terrifying), MUSCLE SPASMS (Muscle spasm from arm to chest), VACCINATION COMPLICATION (Severe reaction/shot made her feel worse), ARTHRALGIA (Knee hurt) and NEURALGIA (Periodic neurologic pain) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In January 2021, SARS-CoV-2 test: positive (Positive) Patient was diagnosed with COVID back in Jan 2021.         The concomitant medication included was non specified blood pressure medication.  No treatment information was provided by reporter. Company comment: 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-2021-267583 (Patient Link).; 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.