A case of giant cell myocarditis associated with a progressive disturbance in the conduction system

A 73 year old male patient with a history of pulmonary tuberculosis was admitted to our department because of dyspnea and abdominal pain. The chest X-ray film on admission showed bilateral lung congestion. The ECG showed atrial fibrillation, left axis deviation and incomplete right bundle branch block. Five days after admission, the ECG changed into sinus rhythm and complete right bundle branch block. Eight days after admission, the patient complained of chest pain and the ECG showed ST elevation in II, III, aVF, reciprocal ST depression in V, and complete A-V block with junctional rhythm. Emergency coronary angiography revealed no significant stenosis. Echocardiography showed reduced contraction of the inferior wall and diffuse granular echoes in the myocardium. Light microscopic study revealed fibrosis, infiltration of eosinophils and histiocytes, degenerated myocardium and multinucleated giant cells. Some of the giant cells were morphologically similar to myocardium, so the myocardium might be a place of immunological reaction.