heart racing and pounding; glands in neck were swollen; having acid problems with gas; tightness in her chest; Little problem with reflux; This is a spontaneous report from a contactable consumer. A 75-year-old female patient received first dose of BNT162B2 (BNT162B2) via an unspecified route of administration, administered in Arm Right on 10Mar2021 at 13:10 (Batch/Lot Number: EN6207) as DOSE 1, SINGLE for covid-19 immunization. Medical history included ongoing Discoid lupus, ongoing Blood pressure high, ongoing Spondylosis, ongoing Allergies, ongoing diverticulitis, ongoing Pre-diabetic (In 2019 she became diabetic, but when she went back to her doctor it had gone down so she is now back to pre-diabetes), ongoing Collapsed mitral valve and Diabetic (from 2019 to an unknown date In 2019 she became diabetic, but when she went back to her doctor it had gone down so she is now back to pre-diabetes). Had a yearly physical on 3Mar2021, and is unsure whether or not she received a Flu shot at that appointment. AEs following prior vaccinations includes nothing other than pains or a slight headache when she gets the Flu shot; really makes her feel bad. She thinks she took a Tylenol when she got home on 03Mar2021. No Lot/NDC/Expiry to provide for any of the Flu shots she has had. For some people it makes them sick, but she normally takes just a Tylenol and goes to bed and feels better when she wakes up. Concomitant medication includes cyanocobalamin (B12 [CYANOCOBALAMIN]) taken for an unspecified indication, start and stop date were not reported. The patient experienced heart racing and pounding on 15Mar2021 (reported as 5 days later), glands in neck were swollen on 14Mar2021 (reported as 4 days later) and having acid problems with gas, tightness in her chest and little problem with reflux on Mar2021 (unspecified date). It was reported that on 10Mar2021, she had her 1st dose of the Covid 19 Vaccine. 4 days later, that afternoon, her glands in her neck were swollen. She rubbed them down with alcohol, and took Tylenol. The next morning, which was day 5 after the shot, her heart was racing and pounding when she woke up. She didn't do anything about it at that time because she thought maybe it would go away, but eventually she went to the ER and was checked out. The doctor in the ER said it was not from Covid 19 vaccine. States that she was also having acid problems with gas and tightness in her chest. She went back to the ER; they checked her out again and sent her home. They wanted her to stay so they could do an upper GI, but she wasn't fully vaccinated yet. She called FDA, and was told it sounded like side effects from the vaccine and to go back to ER, so she went back and and took the paper with her that she got from the FDA, but she was told the same thing. So, she decided to let them admit her to see if they could find out what the problem was. She wore a heart monitor for 2 days, but they didn't see anything, and she had a barium test but they only saw a little problem with reflux. When she was discharged, she went to her primary doctor's office and was explaining to them what was going on, and also went to a cardiologist who gave her a heart monitor which she wore for about 7 days, but nothing was seen on the heart monitor. States that she saw a Neurologist on 03Mar2021 before she got the 1st dose of the vaccine. They took blood work, and she was on B12, and they told her that could affect her nervous system. Caller clarifies that the doctor called her during that time and told her to start taking the B12, she doesn't really remember if she was on the B12 or not when got the 1st dose, but she thinks she was. The patient was hospitalized for heart racing and pounding for 2 days. The patient underwent lab tests and procedures which included Barium test (Barium swallow): only saw a little problem with reflux on Mar2021, Cholesterol (blood cholesterol): excellent on 2021, Blood work (blood test): unknown on 03Mar2021, Heart monitor (cardiac monitoring): nothing wrong on Mar2021, chest x-ray: unknown result on 2021, EKG (electrocardiogram): fine on 2021. Therapeutic measures were taken as a result of glands in neck were swollen. Outcome of the events was unknown.  Follow-up attempts are completed. No further information is expected.