Giant cell myocarditis: Importance of prompt diagnosis and management
Aurora L, Abuzaanona A, Mawri S, Raheja S, Michaels A, Williams C. Giant cell myocarditis: Importance of prompt diagnosis and management. J Card Fail. 2017;23(8):S94-S95.
J Card Fail
Background: Giant Cell Myocarditis (GCM) is a rapidly progressive myocardial disease that presents with a wide variety of non-specific clinical characteristics and requires a high index of suspicion for prompt diagnosis and treatment. We present two such cases to demonstrate the variances and highlight the need for early pathologic diagnosis. Case 1: Young female with no medical history presented with nausea and abdominal pain. She became febrile and hemodynamically unstable. Electrocardiogram (EKG) dem-onstrated sub-endocardial injury and a troponin was indeterminate. Rhythm deteriorated to ventricular tachycardia. Echocardiogram showed ejection fraction (EF) 30%. Cardiac MRI revealed myocarditis. Case 2: Elderly male presented with subacute respiratory congestion and progressive oral intolerance. Patient was tachycardic and labs showed elevated transaminases. EKG showed wide-complex tachycardia and troponin rose to 12.8 ng/mL. Echocardiogram revealed a dilated left ventricle, global hypokinesis, and EF 10%. Decision-making (1): Course was complicated by ventricular fibrillation, refractory to Amiodarone. She underwent endomyocardial biopsy (EMB), which confirmed GCM (Fig. 1). Despite initiation of steroids and a calcineurin inhibitor, arrhythmias persisted and the patient was listed for a heart transplant. Repeat cardiac MRI showed improving inflammation, at the cost of wall thinning and hypokinesis (Fig. 2). Decision-making (2): Acute abdominal pathologies were excluded and worsening chemistries were attributed to evolving cardiogenic shock, presumed viral in origin. He continued to decompensate, requiring vasopressors and inotropes, escalating to mechanical support with venoarterial extracorporeal membrane oxygenation (ECMO). 3 days later, due to development of thrombi within the ECMO circuit, bilateral ventricular assist devices were placed and an EMB was done. He continued to decompensate and expired. Biopsy results confirmed GCM. Conclusion: This case series highlights the need for early recognition of GCM, which often requires mechanical circulatory support and/or orthotopic heart transplant. The most common manifestations of GCM are heart failure, ventricular arrhythmias, and atrioventricular block. Prognosis is dependent on timely EMB, aggressive immunosuppression, and heart failure therapy that can increase mean and transplant free survival in 2/3 of cases.