experienced increased heart rate; Caller got scared and delayed her second dose until 07Aug2021; chest pain; D-Dimer HS level is high; This is a spontaneous report from a contactable pharmacist (patient). A 45-year-old female patient BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE), dose 2 via an unspecified route of administration on 07Aug2021 18:00 (Lot Number: EW0198) (at age of 45-year-old) as DOSE 2, SINGLE for covid-19 immunisation.  The patient medical history and concomitant medications were not reported. The patient previously took the first dose of BNT162B2 on 06Mar2021 (at age of 45-year-old) (Lot Number: EN6205) for COVID-19 Immunization and experienced a tachycardia response, prickling pain all over body, jerking body, headache, and left side of face was tingling. The patient experienced increased heart rate (medically significant) on 07Aug2021, chest pain(non-serious) on Aug2021, d-dimer hs level is high (non-serious) on Aug2021, caller got and delayed her second dose until 07aug2021 (inappropriate schedule of product administration) (non-serious) on 07Aug2021. Event details: The patient received her first dose of the Pfizer Covid-19 Vaccine on 06Mar2021 and experienced a tachycardia response. The patient got scared and delayed her second dose until 07Aug2021. For the past week she has experienced increased heart rate with any activity she does.  Her heart rate remains stable while at rest.  Any movement can cause her heartrate to go up to as much as 124 beats per minute that she recorded. But, she has also experienced her heart rate drop to 58 beats per minute. She says it fluctuates. Caller's doctor tested her CK and Troponin levels and they both came back as normal.  She read an article that said that patients with a diagnosis of COVID-19 can experience an increase to their heartrate and blood pressure.  She read that the antibodies triggers the receptors to cause the increase and she thinks that the Pfizer COvid-19 Vaccine acts in the same way. Received the Pfizer COVID vaccine second dose on Saturday, 07Aug2021. For past week, heart rate has been increased. On Monday (Aug2021), went to primary doctor and was sent to a cardiologist. Cardiologist did ECG and said it was ok. Thursday (Aug2021) had chest pain, got scared and went to the ER. There, the ER did all the tests, X-ray, CPA, and the blood test to check Troponin and CK level, was told everything was ok. Was told her D-Dimer HS level is high. Discharged and sent home. Put on a Holter Monitor. Wearing Holter monitor since Friday (13Aug2021) , took it off today (16Aug2021)and sent to the lab. Heart rate was  still high. Sitting in bed, heart rate is ok, from 80-100. If she started moving, standing up, or doing light housework, heart rate jumps up really high. Jumps to 112-121. Cannot do anything else for the whole week. If she's resting, she's ok. Then moving around the house, heart rate skyrockets to 120. Has appointment with cardiologist on 28Aug2021 for an ECHO to find out if anything is wrong. Received second dose on 07Aug2021 at 18:00. By 20:00 on 07Aug2021, she noticed the increase in heart rate. She went to the hospital, but was not admitted. Confirmed she was discharged from the Emergency Room. The outcome of the events was unknown.; Sender's Comments: Based on strong temporal relationship the causal association between the event heart rate increased and the usage of the vaccine cannot be 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 RAs, Ethics Committees, and Investigators, as appropriate.