weird pain in the middle of her chest; feels like heartburn; Third Dose: muscle spams in the heart; Third Dose: Back muscle spasms; Pfizer covid vaccine the third dose, the booster dose; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 57 year-old female patient received bnt162b2 (BNT162B2), administered in arm left (upper left arm), administration date 19Nov2021 14:30 (Lot number: FD0809) at the age of 57 years as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "food intolerances like gluten" (unspecified if ongoing); "food intolerances like dairy" (unspecified if ongoing); "food intolerances like corn" (unspecified if ongoing). Family history included: "genetic blood clotting: thrombophilia" (unspecified if ongoing), notes: genetic blood clotting, the caller only has one of 2 genes. There were no concomitant medications. Vaccination history included: Bnt162b2 (First Dose: lot ER2613, NDC and expiration date unknown.), administration date: 18Mar2021, when the patient was 56 years old, for COVID-19 Immunization, reaction(s): "sore arm" and "lightheaded"; Bnt162b2 (Second Dose: lot ER8737, NDC and expiration date unknown.), administration date: 08Apr2021, when the patient was 56 years old, for COVID-19 Immunization, reaction(s): "sore arm" and "lightheaded", reported as the only thing that happened after the first two doses of the Pfizer covid vaccine is that the caller got lightheaded like she got unplugged and plugged back in. This happened 3 days after getting the vaccines and that was the only thing that happened other than the sore arm. The following information was reported: IMMUNISATION (medically significant) with onset 19Nov2021, outcome "unknown", described as "Pfizer covid vaccine the third dose, the booster dose"; CARDIOMYOPATHY (medically significant) with onset 29Nov2021 07:50, outcome "recovering", described as "Third Dose: muscle spams in the heart"; MUSCLE SPASMS (medically significant) with onset 21Nov2021, outcome "not recovered", described as "Third Dose: Back muscle spasms"; CHEST PAIN (non-serious), outcome "unknown", described as "weird pain in the middle of her chest"; DYSPEPSIA (non-serious), outcome "unknown", described as "feels like heartburn". The events "third dose: muscle spams in the heart" and "third dose: back muscle spasms" were evaluated at the emergency room visit. The patient underwent the following laboratory tests and procedures: laboratory test: unknown result, notes: They did a lot of tests on the caller today and didn't find anything of concern. Therapeutic measures were taken as a result of cardiomyopathy, muscle spasms. Clinical courses: The caller just got back for the emergency room because she had muscle spams in the heart, it was gripping. The caller has been dealing with back spasms all last week and chocked it up to throwing out her back. The back muscle spasms go up her back and along her spine. They did all sorts of tests at the hospital. It seemed really strange that this happened because she is otherwise healthy. The doctors didn't see any abnormal heart activity and the caller has 3 baby aspirins just in case. The caller doesn't know if the back and heart muscle spasms are related. On 19Nov2021 the caller got her third dose and its strange that something like this would happen 10 days later and it may not be related to the vaccine. The caller has been standing because when she sits on a hard surface that's when the spasms go up her back, its really painful its worse than childbirth. The caller's heart muscle spasms happened at 7:50 this morning, it happened every minute for approximately 15 minutes and had someone drive her to the hospital. The caller was never admitted as a patient but was seen in the emergency room. The caller still feels some weird pain in the middle of her chest and it feels like heartburn even though she didn't eat anything spicy.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202101686201 similar report from same reporter