irregular heart beat; congestion in the chest; dizzy/the dizziness she was having and feeling now after getting the vaccine was definitely more noticeable; This is a spontaneous report from a contactable consumer (the patient). A 73-year-old female patient received the first dose BNT162B2 (PFIZER-BIONTECH COVID-19 MRNA VACCINE), via an unspecified route of administration in the left deltoid/ left upper arm in the shoulder on 26Jan2021 around 14:00 (at the age of 73-years-old) as a single dose for COVID-19 immunization. The patient's medical history included: stroke about 4-5 years ago in June, dizziness, blood pressure. The patient also had difficulty writing stuff down; besides having a number issue, she had issues writing numbers down. Concomitant medication included apixaban (ELIQUIS) from an unspecified date and ongoing as a blood thinner. The patient stated she was on ten different medications. These medications were added after the stroke. Before the stroke she was not on any medication. The patient did not have any vaccines administered on same date of the Pfizer COVID vaccine. The patient got the pneumonia vaccine (unspecified), but thinks it was longer than 4 weeks before. She did not remember, but she believed it had been a month and a half to 2 months (at the age of 73-years-old) since getting the pneumonia vaccine for immunization. The patient had the COVID shot on Tuesday of this week (26Jan2021), and she didn't seem to have much of a reaction other than what they expected except at 21:00 that night, she got pretty dizzy. She was still dizzy now. It was enough for her to have to walk with a cane in order to try and keep herself leveled. She could not move quickly. She did not know why she had this reaction. She called her doctor the next day, and he did not understand why. She mentioned she was reading material and saw this could be a severe side effect/situation. The doctor mentioned they were trying to find out if it was related to the blood pressure. She wanted to know if this is part of the side effect, dizziness? When the patient was attempting to provide the zip code, she stated her mind was going blank and could not remember the zip code. She later found something with it written on it and provided those details.  She explained she had a stroke when trying to provide her current age. She stated numbers are hard for her. She stated she would be 74 in March, and questioned how old that would make her now, she later confirmed as 73. She read information today about the COVID vaccine, and she saw that one should be cautious about the vaccine if have a bleeding disorder, and she commented she was on a blood thinner. She went to the doctor last week and mentioned she was having dizziness. She clarified she had dizziness before getting the COVID-19 vaccine. When she went to the doctor, they thought it was due to blood pressure as the problem. They changed her blood pressure medication by placing on a higher dose. Then she started having more dizziness, and the dose was taken back down to the dose she was on before. She also added, she has an irregular heartbeat (unspecified date). She went to the doctor because of congestion in the chest (unspecified date); that was why she went to the doctor. The doctor asked about dizziness and she said she was having a little. However, the dizziness she was having and feeling now after getting the vaccine was definitely more noticeable. The clinical outcome of dizzy was recovering (as reported). The outcome of the other events was unknown.  Information on Lot/Batch number has been requested.