Abstract 15317: An Unusual Case of Recurrent Chest Pain: Lymphocytic Myocarditis

Abstract

Case Presentation: A 42-year-old male with a past medical history of recurrent myopericarditis treated with a combination of NSAIDs, colchicine, and steroids presented for left-sided chest pain. The pain first recurred when he attempted a prednisone taper and he was started on Anakinra. Upon presentation, physical examination and laboratory findings were within normal limits. Echocardiography and electrocardiogram were within normal limits. Cardiac magnetic resonance imaging (CMR) showed transmural enhancement of the basal-mid inferolateral segments and patchy mid-myocardial enhancement in the basal-mid anterolateral segments. Nuclear medicine PET showed FDG uptake in the basal anteroseptal, anterolateral, inferolateral, inferior, and apical segments suggestive of active inflammation. Initially, the diagnosis was thought to be recurrent myopericarditis of unknown etiology. Subsequent right heart catheterization with endomyocardial biopsy (EMB) showed mononuclear infiltrates in the interstitium associated with myocyte infiltration and focal moderate interstitial fibrosis. Due to his clinical, imaging, and pathologic findings, he was diagnosed with lymphocytic myocarditis. His anti-inflammatory therapy regimen was reinstated, and he was started on Mycophenolate Mofetil. On follow-up, the patient had significant symptomatic improvement. Discussion: Lymphocytic myocarditis is a pattern of myocardial inflammation that is typically associated with autoimmune and idiopathic causes. Myocarditis frequently manifests with signs and symptoms of heart failure, including chest pain, dyspnea, and arrhythmias. Diagnosis of myocarditis is often supported by CMR and FDG-PET findings, however, EMB is the gold standard for the diagnosis of myocarditis. Treatment is generally supportive, though immunomodulatory therapies have gained increased popularity due to benefits in treating symptoms and preventing complications of heart failure.