Cardiac Arrest; Patient was found pulseless and breathless 20 minutes following the vaccine administration.; Patient was found pulseless and breathless 20 minutes following the vaccine administration.; This is a spontaneous report from a contactable other healthcare professional (HCP). A 66-year-old female patient (pregnant at the time of vaccination: no) received the second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, lot number: EL1284) via intramuscular at left arm on 11Jan2021 12:15 PM at single dose for COVID-19 immunization. Medical history included diastolic CHF, spinal stenosis, morbid obesity, epilepsy, pulmonary hypertension and COVID-19 (Prior to vaccination, the patient was diagnosed with COVID-19). The patient received medication within 2 weeks of vaccination included amiodarone, melatonin, venlafaxine hydrochloride (EFFEXOR), ibuprofen, aripiprazole (ABILIFY), lisinopril, cranberry capsules, diltiazem, paracetamol (TYLENOL), famotidine, furosemide (LASIX [FUROSEMIDE]), ipratropium bromide, salbutamol sulfate (IPRATROPIUM/ALBUTEROL), buspirone, senna alexandrina leaf (SENNA [SENNA ALEXANDRINA LEAF]), polyethylene glycol 3350 and morphine. The patient did not receive any other vaccines within 4 weeks prior to the COVID vaccine. Patient used took Penicillin, propranolol, quetiapine, topiramate, Lamictal and had allergy to them. Patient used took the first dose of BNT162B2 (lot number: EJ1685) via intramuscular at right arm on 21Dec2020 12:00 PM at single dose for COVID-19 immunization. Since the vaccination, the patient been tested for COVID-19 (Sars-cov-2 PCR) via nasal swab on 06Jan2021, covid test result was negative. Patient was found pulseless and breathless 20 minutes following the vaccine administration (11Jan2021 12:30 AM). MD found no signs of anaphylaxis. Patient died on 11Jan2021 12:30 AM because of cardiac arrest. No treatment received for the events. Outcome of pulseless and breathless was unknown. the autopsy was performed, and autopsy remarks was unknown. Autopsy-determined cause of death was unknown.  It was reported as non-serious, not results in death, Life threatening, caused/prolonged hospitalization, disabling/Incapacitating nor congenital anomaly/birth defect.; Sender's Comments: Based on the available information this patient had multiple underlying medical conditions including morbid obesity, diastolic CHF, epilepsy, pulmonary hypertension and COVID-19 diagnosed prior to vaccination. All these conditions more likely contributed to patients cardiac arrest resulting in death. However, based on a close temporal association ("Patient was found pulseless and breathless 20 minutes following the second dose of BNT162B2 vaccine administration, contributory role of BNT162B2 vaccine to the onset of reported events cannot be completely excluded. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate.; Reported Cause(s) of Death: Cardiac arrest; Autopsy-determined Cause(s) of Death: autopsy remarks was unknown. Autopsy-determined cause of death was unknown