pneumonia; Hemorrhagic effusion/ drained 1 liter of fluid; pre-cardiac tamponade; Pericarditis with hemorrhagic effusion fluid; left pleural effusion/ bilateral pleural effusions; Fever greater than 101.5; His EKG showed atrial fibrillation and a bundle branch block; His EKG showed atrial fibrillation and a bundle branch block; palpitations; chest pain/ sternal chest pain; chest discomfort; sternal chest pain; pain when lying on his left side at night; Pain with taking a deep breath; This spontaneous case was reported by a nurse and describes the occurrence of PALPITATIONS (palpitations), PLEURAL EFFUSION (left pleural effusion/ bilateral pleural effusions), PYREXIA (Fever greater than 101.5), BUNDLE BRANCH BLOCK (His EKG showed atrial fibrillation and a bundle branch block), ATRIAL FIBRILLATION (His EKG showed atrial fibrillation and a bundle branch block), PNEUMONIA (pneumonia), HAEMOTHORAX (Hemorrhagic effusion/ drained 1 liter of fluid), CARDIAC TAMPONADE (pre-cardiac tamponade) and PERICARDITIS (Pericarditis with hemorrhagic effusion fluid) in a 48-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 028L20A and 039K20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concomitant products included IBUPROFEN and COLCHICINE for an unknown indication.   On 08-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 05-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 22-Jul-2021, the patient experienced CHEST PAIN (chest pain/ sternal chest pain), CHEST DISCOMFORT (chest discomfort), CHEST PAIN (sternal chest pain), PAIN (pain when lying on his left side at night) and DYSPNOEA (Pain with taking a deep breath). On 12-Aug-2021, the patient experienced PALPITATIONS (palpitations) (seriousness criteria hospitalization prolonged, medically significant and life threatening), BUNDLE BRANCH BLOCK (His EKG showed atrial fibrillation and a bundle branch block) (seriousness criteria hospitalization prolonged, medically significant and life threatening) and ATRIAL FIBRILLATION (His EKG showed atrial fibrillation and a bundle branch block) (seriousness criteria hospitalization prolonged, medically significant and life threatening). On an unknown date, the patient experienced PLEURAL EFFUSION (left pleural effusion/ bilateral pleural effusions) (seriousness criteria hospitalization prolonged, medically significant and life threatening), PYREXIA (Fever greater than 101.5) (seriousness criteria hospitalization prolonged, medically significant and life threatening), PNEUMONIA (pneumonia) (seriousness criteria hospitalization prolonged, medically significant and life threatening), HAEMOTHORAX (Hemorrhagic effusion/ drained 1 liter of fluid) (seriousness criteria hospitalization prolonged, medically significant and life threatening), CARDIAC TAMPONADE (pre-cardiac tamponade) (seriousness criteria hospitalization prolonged, medically significant and life threatening) and PERICARDITIS (Pericarditis with hemorrhagic effusion fluid) (seriousness criteria hospitalization prolonged, medically significant and life threatening). At the time of the report, PALPITATIONS (palpitations), PLEURAL EFFUSION (left pleural effusion/ bilateral pleural effusions), PYREXIA (Fever greater than 101.5), BUNDLE BRANCH BLOCK (His EKG showed atrial fibrillation and a bundle branch block), ATRIAL FIBRILLATION (His EKG showed atrial fibrillation and a bundle branch block), PNEUMONIA (pneumonia), HAEMOTHORAX (Hemorrhagic effusion/ drained 1 liter of fluid), CARDIAC TAMPONADE (pre-cardiac tamponade), PERICARDITIS (Pericarditis with hemorrhagic effusion fluid), CHEST PAIN (chest pain/ sternal chest pain), CHEST DISCOMFORT (chest discomfort), CHEST PAIN (sternal chest pain), PAIN (pain when lying on his left side at night) and DYSPNOEA (Pain with taking a deep breath) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 12-Aug-2021, Electrocardiogram: atrial fibrillation and bundle branch block (abnormal) Showed atrial fibrillation and bundle branch block. On an unknown date, Angiogram: pleural effusion and pericarditis (abnormal) ruled out coronary artery embolism, showed left pleural effusion and pericarditis with hemoohagic effusion fluid. On an unknown date, Body temperature: 101.5 (High) 101.5. On an unknown date, SARS-CoV-2 test: negative (Negative) Negative. On an unknown date, Troponin: normal (normal) Normal. On an unknown date, X-ray: pleural effusion and pericarditis (abnormal) ruled out coronary artery embolism, showed left pleural effusion and pericarditis with hemoohagic effusion fluid.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered PALPITATIONS (palpitations), PLEURAL EFFUSION (left pleural effusion/ bilateral pleural effusions), PYREXIA (Fever greater than 101.5), BUNDLE BRANCH BLOCK (His EKG showed atrial fibrillation and a bundle branch block), ATRIAL FIBRILLATION (His EKG showed atrial fibrillation and a bundle branch block), PNEUMONIA (pneumonia), HAEMOTHORAX (Hemorrhagic effusion/ drained 1 liter of fluid), CARDIAC TAMPONADE (pre-cardiac tamponade), PERICARDITIS (Pericarditis with hemorrhagic effusion fluid), CHEST PAIN (chest pain/ sternal chest pain), CHEST DISCOMFORT (chest discomfort), CHEST PAIN (sternal chest pain), PAIN (pain when lying on his left side at night) and DYSPNOEA (Pain with taking a deep breath) to be possibly related.    EKG showed atrial fibrillation and a bundle branch block. Also received a chest Xray and CT angiogram of chest which ruled out pulmonary embolism, but showed a left pleural effusion, and pericarditis with hemorrhagic effusion fluid. So much fluid like precardiac tamponade. The pericarditis was idiopathic. Admitted to hospital for pericarditis where they surgically removed 1L of fluid and cut out a piece of the back of heart. Intubated during this procedure and discharged from the hospital and since returned to hospital 2 additional time for having a fever more than 101.5F. The first was attributed to pericarditis and second was due to pericarditis and pneumonia. At the most recent hospital visit, they found bilateral pleural effusions on his chest x-ray, but the fluid had not come back around heart. The pneumonia was projected to be a postsurgical complication of his procedure. Tested for COVID-19 at all hospitalizations, but all tests were negative. was experiencing fever >101.5 again.  Company Comment: This case concerns a 48-year-old male patient with no relevant medical history, who experienced the unexpected events of Palpitations, Atrial Fibrillation, Bundle Branch Block, Pyrexia, Pneumonia, Pleural Effusion, Haemothorax, Cardiac Tamponade and the expected event of Pericarditis. The events Palpitations, Atrial Fibrillation, and Bundle Branch Block, occurred at 7 months 5 days after receiving the second dose of mRNA-1273 (Moderna COVID-19 Vaccine) while the events of Pyrexia, Pneumonia, Pleural Effusion, Haemothorax, Cardiac Tamponade, and Pericarditis occurred on an unknown date with outcome of hospitalization. The rechallenge was unknown as there's no information available about the first dose. The The event of pericarditis is consistent with the current understanding of the mechanism of action of the vaccine. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report.; Sender's Comments: This case concerns a 48-year-old male patient with no relevant medical history, who experienced the unexpected events of Palpitations, Atrial Fibrillation, Bundle Branch Block, Pyrexia, Pneumonia, Pleural Effusion, Haemothorax, Cardiac Tamponade and the expected event of Pericarditis. The events Palpitations, Atrial Fibrillation, and Bundle Branch Block, occurred at 7 months 5 days after receiving the second dose of mRNA-1273 (Moderna COVID-19 Vaccine) while the events of Pyrexia, Pneumonia, Pleural Effusion, Haemothorax, Cardiac Tamponade, and Pericarditis occurred on an unknown date with outcome of hospitalization. The rechallenge was unknown as there's no information available about the first dose. The The event of pericarditis is consistent with the current understanding of the mechanism of action of the vaccine. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report.