shortness of breath / breathing problems; shaking a lot; heart problems; heart pounding; skipping beats; This case was received via an unknown source (no reference has been entered for a health authority or license partner) on 26-Oct-2021 and was forwarded to Moderna on 26-Oct-2021.    This spontaneous case was reported by a consumer and describes the occurrence of DYSPNOEA (shortness of breath / breathing problems), TREMOR (shaking a lot), CARDIAC DISORDER (heart problems), PALPITATIONS (heart pounding) and EXTRASYSTOLES (skipping beats) in a 20-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.     The patient's past medical history included COVID-19 in January 2021. Concurrent medical conditions included Seasonal allergy, Drug allergy (Prozac heart related: palpitations, shortness of breath, couldn't breath properly, & throat tightening up.), Drug allergy (Zoloft heart related: palpitations, shortness of breath, couldn't breath properly, & throat tightening up.) and Drug allergy (Zosyn rashes, face redness, & breathing problems.).   On 15-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In May 2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 15-Apr-2021, the patient experienced DYSPNOEA (shortness of breath / breathing problems), TREMOR (shaking a lot), CARDIAC DISORDER (heart problems), PALPITATIONS (heart pounding) and EXTRASYSTOLES (skipping beats). In April 2021, DYSPNOEA (shortness of breath / breathing problems), TREMOR (shaking a lot), CARDIAC DISORDER (heart problems), PALPITATIONS (heart pounding) and EXTRASYSTOLES (skipping beats) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In January 2021, SARS-CoV-1 test: positive (Positive) SARS-CoV-1 test: positive.         Treatment included cold remedies, eating healthier and taking rest.  No concomitant drug information was provided.  This case concerns a 20-year-old, female patient with medical history previous drug allergies with heart related symptoms, who experienced the unexpected, non- serious and event of Extrasystoles. The event occurred immediately after first dose of Spikevax. The rechallenge was positive, as the patient states that she had similar symptoms after the second dose. The medical history of drug allergies with heart related symptoms remains as a confounder. The benefit risk relationship of vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 26-Oct-2021: Significant follow-up, patient information , events, relevant medical history, lab data and treatment information updated; Sender's Comments: This case concerns a 20-year-old, female patient with medical history previous drug allergies with heart related symptoms, who experienced the unexpected, non- serious and event of Extrasystoles. The event occurred immediately after first dose of Spikevax. The rechallenge was positive, as the patient states that she had similar symptoms after the second dose. The medical history of drug allergies with heart related symptoms remains as a confounder. The benefit risk relationship of vaccine is not affected by this report.