heartbeats irregular; painful arm/ aches and pains through then leading to irregular heartbeat; this is a spontaneous report received from a contactable consumer from a regulatory authority. other case identifier(s): gb-mhra-vac-202202200924002130-rlnoq, gb-mhra-adr 26626254. a 61-year-old female patient received bnt162b2 (pfizer-biontech covid-19 vaccine, lot number and expiration date were not reported), via an unspecified route of administration as dose number unknown, single for covid-19 immunization. the patient's relevant medical history and concomitant medications were not reported. the following information was reported: heart rate irregular (life threatening), outcome "recovering", described as "heartbeats irregular"; pain in extremity (non-serious), outcome "unknown", described as "painful arm/ aches and pains through then leading to irregular heartbeat". therapeutic measures were taken as a result of heart rate irregular, pain in extremity. physiotherapy was recommended for painful arm. no follow-up attempts are possible; information about lot/batch number cannot be obtained. no further information is expected