Patient is a 69-year-old woman with newly diagnosed pericarditis in March 2021, hypertension, hyperlipidemia, and hypothyroidism, who presented to the Emergency Department (ED) with progressively worsening chest pain, dyspnea, and fatigue. Patient was in her usual state of health until 3/1/2021, when she developed sudden-onset pain "across the entire chest".  She shares that her symptoms "came out of the blue", as "suddenly one day, everything just hurt".  She saw her primary care physician, who initially felt her symptoms were due to acid reflux.  As such, the patient started "eating antacids and omeprazole like candy".  However, her chest pain persisted, prompting her to follow up with her primary care physician on 3/16/2021.  At that time, ECG reportedly showed normal sinus rhythm and no acute changes.  CT of the chest, abdomen, and pelvis with contrast showed abnormal enhancement and thickening of the pericardium with trace pericardial fluid, consistent with pericarditis.  The patient was therefore started on colchicine and an ibuprofen taper.   On 4/5/2021, Patient sent a myVM portal message to her primary care physician and cardiologist, expressing her belief that her chest pain has remained unchanged over the past month.  She continues to experience a constant burning sensation throughout her chest, aggravated by deep inspiration and alleviated by lying flat on her back.  She shares that walking up the stairs at home leaves her "breathless".  Associated symptoms include subjective fevers, chills, and night sweats.  Given these symptoms, Patient underwent a chest x-ray, which showed findings consistent with an enlarging pericardial effusion.  Patient was then advised to present to the ED for further workup as an inpatient.   At time of hospital admission, patient endorses persistent chest pain during inspiration.  Prior to 3/1/2021, she has never experienced these symptoms and reports no history of pericarditis.  The most strenuous physical activity she has undertaken in the last month include working in the garden and caring light boxes down the stairs.  She is most concerned about the fluid around her heart.  Patient reports no nausea, vomiting, palpitations, constipation, diarrhea, or abdominal pain.  Of note, the patient developed pericarditis 10 days after her second COVID-19 vaccine.  Hospital Course        # Sub-acute pericarditis with enlarging pericardial effusion Pericarditis initially diagnosed in March 2021, thought to be potentially from her COVID-19 vaccine given time course as no other clear etiology apparent.  Pt was hemodynamically stable with an elevated jugular venous pressure at time of admission, with CXR consistent with an enlarging pericardial effusion. Echo 04/05 with small circumferential pericardial effusion but no tamponade physiology.  Cardiac MRI on 4/7 with enlargement of moderate-sized pericardial effusion but otherwise negative exam, with no evidence of myocarditis or infiltrative myocardial process. ANA screen negative, rheumatoid factor and anti-CCP not elevated Blood cultures x 2 with no growth - CRP continued to remain > 160 with ibupofen and colchicine. Prednisone 20 mg PO daily was added on 4/7, with subsequent improvement in patient's symptoms.   - Discharged on regimen of prednisone 20 mg PO daily and colchicine 0.3 mg PO daily (reduced from 0.6 mg daily that she was taking prior to admission). She will also continue using ibuprofen 800 mg BID.  - Follow-up with Dr (cardiology) next week to follow-up on hospitalization and decide upon tapering plan for her medications