Cardiac Tamponade and Fatal Arrhythmia Caused by Cardiac Actinomycosis Attributable to Actinomyces meyeri

Abstract

Introduction: We herein report the first case of cardiac tamponade and fatal arrhythmia due to cardiac actinomycosis attributable to Actinomyces meyeri, in which the patient survived through medical management. Case presentation: A 56-year-old Japanese man referred to our hospital with dyspnea and hypotension. The chest CT scan showed a mass in the left upper lobe, cavitary lesion in the left lower lobe (LLL), bilateral pleural effusions and pericardial effusion. He underwent pericardial and pleural drainage, and intravenous ceftriaxone therapy was started. Gram stain and cytologic examination of the pericardial and pleural fluid did not show any organisms and also malignant cells. After the admission, the patient's condition improved, and the pericardial tube was removed on the sixth day. At the ninth day, the patient suddenly became atrial fibrillation and subsequently became asystolic cardiac arrest. Immediate cardiopulmonary resuscitation was performed, which restored sinus rhythm and blood pressure. Thereafter, ultrasound-guided pneumocentesis of the cavitary lesion in the LLL was performed and cultures from the fluid grew A. meyeri. Antibiotics were changed to intravenous penicillin on the 11th day. He completed the total six-month antibiotic therapy and was successfully improved on general condition. Discussion: Cardiac actinomycosis was reported in only 1.2 to 2% of all cases of actinomycosis. Cardiac involvement usually results from the direct extension of thoracic disease. Our patient also had concomitant pulmonary involvements as a probable primary site of infection. The prognosis of actinomycosis depends on early diagnosis, however, the diagnosis is generally hampered by the difficulty in isolation and culture of the organism. In our case, fortunately, we could detect this pathogen by pneumocentesis. Conclusions: To our knowledge, this is the first case who survived cardiac tamponade and fatal arrhythmia caused by cardiac actinomycosis attributable to A. meyeri.