Atrial fibrillation; Heart immediately began rapidly throbbing/ Pounding in my chest; Pounding in my ears; Heart rate which was normally mid 60's/minute would suddenly become 80-100/minute; Periodic dizziness; Shortness of breath; Consistently harder & harder time climbing the 17 stairs to my condo; A even more rapid and pronounced pounding in my chest and ears, accompanied by cold air in the center of my chest; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 73-year-old female patient received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 30Sep2022 as dose 5 (booster), single (Lot number: gj5342) at the age of 73 years for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: BNT162b2 (DOSE 1, SINGLE, Lot number: EL9269), administration date: 13Feb2021, for COVID-19 immunisation; BNT162b2 (DOSE 2, SINGLE, Lot number: EN6198), administration date: 06Mar2021, for COVID-19 immunisation, reaction(s): "atrial fib/erratic heart beat/rapid heartbeat in chest and throat/Alternating episodes of rapid heartbeat in chest and throat that were so strong", "A lump in left breast that was the shape and size of a new erase on a #2 pencil"; BNT162b2 (DOSE 3 (BOOSTER), SINGLE, Lot number: FE3590), administration date: 04Oct2021, for COVID-19 immunisation, reaction(s): "the thumping pulse in the back of my neck became less and less frequent"; BNT162b2 (DOSE 4 (BOOSTER), SINGLE, Lot number: FJ5682), administration date: 15Apr2022, for COVID-19 immunisation, reaction(s): "A even more rapid and pronounced pounding in my chest and ears, accompanied by cold air in the center of my chest", "A even more rapid and pronounced pounding in my chest and ears, accompanied by cold air in the center of my chest", "My heart rate which was normally mid 60's/minute would suddenly become 80-100/minute", "Periodic dizziness", "Shortness of breath", "Also I began having a consistently harder & harder time climbing the 17 stairs to my condo without stopping for a break", "A even more rapid and pronounced pounding in my chest and ears, accompanied by cold air in the center of my chest". The following information was reported: CHEST DISCOMFORT (non-serious) with onset 2022, outcome "not recovered", described as "A even more rapid and pronounced pounding in my chest and ears, accompanied by cold air in the center of my chest"; DECREASED ACTIVITY (non-serious) with onset 2022, outcome "not recovered", described as "Consistently harder & harder time climbing the 17 stairs to my condo"; PALPITATIONS (non-serious) with onset 2022, outcome "not recovered", described as "Heart immediately began rapidly throbbing/ Pounding in my chest"; HEART RATE INCREASED (non-serious) with onset 2022, outcome "not recovered", described as "Heart rate which was normally mid 60's/minute would suddenly become 80-100/minute"; DIZZINESS (non-serious) with onset 2022, outcome "not recovered", described as "Periodic dizziness"; TINNITUS (non-serious) with onset 2022, outcome "not recovered", described as "Pounding in my ears"; DYSPNOEA (non-serious) with onset 2022, outcome "not recovered", described as "Shortness of breath"; ATRIAL FIBRILLATION (medically significant) with onset 08Feb2023, outcome "recovered" (2023). The events "atrial fibrillation", "heart immediately began rapidly throbbing/ pounding in my chest", "pounding in my ears", "heart rate which was normally mid 60's/minute would suddenly become 80-100/minute", "periodic dizziness", "shortness of breath", "consistently harder & harder time climbing the 17 stairs to my condo" and "a even more rapid and pronounced pounding in my chest and ears, accompanied by cold air in the center of my chest" required physician office visit and emergency room visit. The patient underwent the following laboratory tests and procedures: Cardiac stress test: (08Feb2023) Atrial fibrillation; Heart rate: (2022) 80-100/minute; (2022) normally mid 60's/minute; annual physical with my primary care doctor: (2023) unknown results. Therapeutic measures were taken as a result of atrial fibrillation, palpitations, heart rate increased, dizziness, dyspnoea, decreased activity, chest discomfort. Clinical course: Patient's reaction to these vaccines resulted in a previously strong heart now requiring drugs to treat the resulting atrial fibrillation. (patient had typed these reactions on a separate page.) Unfortunately, due to cost of the drug, Patient was not able to afford your Eliquis, which was initially prescribed for during emergency visit. By mid-fall 2022 after taking both boosters, symptoms changed to: A even more rapid and pronounced pounding in chest and ears, accompanied by cold air in the center of chest. Patient's heart rate which was normally mid 60's/minute would suddenly become 80-100/minute. Patient had periodic dizziness and shortness of breath, but it was not constant. The only consistent trigger was drinking ice water. Also Patient began having a consistently harder & harder time climbing the 17 stairs to condo without stopping for a break. For the last 20 + years, Patient had never even been winded when rapidly climbing them. At this point, Patient had to lie down afterwards. Because no one seemed to know what was causing symptoms, Patient ignored these issues until 2023 annual physical with primary care doctor. When she asked how Patient was doing, Patient shared with her that the above symptoms had changed and were becoming more frequent and more disturbing. She ordered a stress test. Before the "stress" part of the test, Patient was given a bottle of water. While it did not have ice in it, it was cold and after drinking about 3 oz., Patient heart immediately began rapidly throbbing. kite Patient was connected to monitors and waiting for the cardiologist to begin the stress test, the nurse suddenly told Patient had gone into atrial fib. They took Patient to the hospital emergency room for treatment. ER stopped A Fib with chemical injection on 08Feb2023 withheld. Currently scheduled to see a cardiologist -meanwhile Patient was on a Beta Blocker + Eliquis which Patient cannot afford to continue taking.; Sender's Comments: Linked Report(s) : US-PFIZER INC-PV202300030622 Same patient, same product (dose 2), different events;US-PFIZER INC-PV202300046822 same patient and different drug dose/events.;US-PFIZER INC-PV202300053157 Same patient, same product (dose 3), different events;US-PFIZER INC-202300122457 Same patient, same product (dose 4), different events;