something not right going with my heart; Diagnosed with Premature Atrial Contraction after booster; Chest Pain; Weakness; High Blood Pressure 182/ unknown mmHg; Dizziness; This spontaneous case was reported by a consumer and describes the occurrence of SUPRAVENTRICULAR EXTRASYSTOLES (Diagnosed with Premature Atrial Contraction after booster), HYPERTENSION (High Blood Pressure 182/ unknown mmHg), CHEST PAIN (Chest Pain), ASTHENIA (Weakness) and CARDIAC DISCOMFORT (something not right going with my heart) in a 74-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 058F21A, 022M20A and 013M20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Drug allergy (Pseudoephedrine), High cholesterol, GERD and Thyroid activity decreased. Concomitant products included PANTOPRAZOLE from 28-Dec-2021 to an unknown date for GERD, METOPROLOL from 28-Dec-2021 to an unknown date for Heart rate, ROSUVASTATIN from 07-Jun-1997 to an unknown date for High cholesterol, GABAPENTIN from 13-Mar-2019 to an unknown date for Nerve pain, LEVOTHYROXINE from 04-Apr-1987 to an unknown date for Thyroid activity decreased.   On 03-Feb-2021 at 10:00 AM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 03-Mar-2021 at 10:00 AM, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 18-Nov-2021 at 11:00 AM, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to .25 milliliter. On 18-Dec-2021, the patient experienced HYPERTENSION (High Blood Pressure 182/ unknown mmHg). 18-Dec-2021, the patient experienced DIZZINESS (Dizziness). On 28-Dec-2021, the patient experienced SUPRAVENTRICULAR EXTRASYSTOLES (Diagnosed with Premature Atrial Contraction after booster), CHEST PAIN (Chest Pain) and ASTHENIA (Weakness). On 28-Dec-2021 at 10:00 PM, the patient experienced CARDIAC DISCOMFORT (something not right going with my heart). The patient was treated with METOPROLOL TARTRATE (oral) for Blood pressure high and Chest pain, at a dose of 25 milligram twice a day. At the time of the report, SUPRAVENTRICULAR EXTRASYSTOLES (Diagnosed with Premature Atrial Contraction after booster), HYPERTENSION (High Blood Pressure 182/ unknown mmHg), CHEST PAIN (Chest Pain), ASTHENIA (Weakness), CARDIAC DISCOMFORT (something not right going with my heart) and DIZZINESS (Dizziness) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In December 2021, Blood thyroid stimulating hormone: high (High) Elevated TSH. On 18-Dec-2021, Blood pressure measurement: 182/unknown (High) High Blood Pressure 182/ unknown mmHg.. On 18-Dec-2021, Heart rate: increased heart rate (High) increased Heart rate.         Patient stated that she did not have a medical history of any type of heart disease and never had high blood pressure. She did not take medications prior to vaccination. She was released from  ER on the same day with a prescription for a Beta blocker and she was wearing a heart monitor.On 28-DEC-2021 she was taken to the doctor where blood test was run, and she did not had a heart attack. She was released at 2:30 AM and was told to Follow up. Company comment: This is a spontaneous case concerning a 74-year-old female patient, with concomitant medication of Levothyroxine suggesting underlying medical history of hypothyroidism, who experienced the non-serious, unexpected AESI event of supraventricular extrasystoles approximately 40 days after the third dose mRNA 1273 vaccine and other non-serious events. One month after the booster dose, the patient experienced hypertension (High Blood Pressure 182/ unknown mmHg) and dizziness. 10 days after, she experienced supraventricular extrasystoles, chest pain and asthenia. She went to the emergency room, was diagnosed with Premature Atrial Contraction and was treated with Metoprolol Tartrate (oral) for Blood pressure high and Chest pain, at a dose of 25 milligram twice a day. On the same month of the events, the patient had Elevated TSH. The mentioned concomitant medication remains a confounder for supraventricular extrasystoles. The benefit-risk relationship of mRNA 1273 vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 15-Feb-2022: Significant Follow Up Received on 15-FEB-2022 included Patient demographics added, medical history and lab data updated, Anatomical location of all three doses updated, Dose for third dose added, Concomitant medications added, start date of events updated, new event added.; Sender's Comments: This is a spontaneous case concerning a 74-year-old female patient, with concomitant medication of Levothyroxine suggesting underlying medical history of hypothyroidism, who experienced the non-serious, unexpected AESI event of supraventricular extrasystoles approximately 40 days after the third dose mRNA 1273 vaccine and other non-serious events. One month after the booster dose, the patient experienced hypertension (High Blood Pressure 182/ unknown mmHg) and dizziness. 10 days after, she experienced supraventricular extrasystoles, chest pain and asthenia. She went to the emergency room, was diagnosed with Premature Atrial Contraction and was treated with Metoprolol Tartrate (oral) for Blood pressure high and Chest pain, at a dose of 25 milligram twice a day. On the same month of the events, the patient had Elevated TSH. The mentioned concomitant medication remains a confounder for supraventricular extrasystoles. The benefit-risk relationship of mRNA 1273 vaccine is not affected by this report.