Reported Symptoms: 10043071:TACHYCARDIA; Narrative: Patient presented to the urgent care on 10/21/24 with cold and flu symptoms following strep throat exposure. While being in urgent care the patient was given a covid and influenza vaccine. Patient presented to her local emergency department on 10/21/24 with angina and feeling like her heart was racing. EKG showed narrow complex tachycardia with maximum heart rate of 211. Patient was given adenosine with no resolution so she was started on heparin and diltiazem continuous infusions for atrial flutter with RVR. Troponin inreased to 170 from 51 showing demand ischemia. Patient was transferred to a highter acuity facility and the patient spontaneously converted to a normal sinus rhythm . Patient was transitioned to metoprolol and apixaban on discharge. Patient was discharged on 10/23/24. Follow-up ECG from 12/4/24 showed normal function of the left ventricle. Facility physician suspected the cause of this event was the Covid vaccine. Patient had no previous cardiac diagnoses. Patient has no other vaccine reactions listed. Other Relevant HX; Other: TACHYCARDIA