Cardiac magnetic resonance imaging in giant cell myocarditis: intriguing associations with clinical and pathological features

Giant cell myocarditis (GCM) is rare and often fatal. Proper diagnosis is crucial, because immunosuppressive therapy has been reported to increase the median transplant-free survival time from 3.0 to 12.3 months.1 Although endomyocardial biopsy plays an essential role in early diagnosis, it may yield false-negative results. Imaging examinations including cardiac magnetic resonance (CMR) may facilitate the diagnosis, but the associations between specific CMR findings and the clinical features and pathological findings remain unclear. We present a patient with characteristic CMR findings, with intriguing associations with the clinical features and pathological findings of the biopsy and autopsy. A 73-year-old woman presented with acute chest pain and dyspnea that had continued for 7 hours. Her medical history was unremarkable, with the exception of uveitis and dyslipidemia. Initial examination showed resting blood pressure 132/83 mm Hg, heart rate 103 bpm, and respiratory rate 17 breaths/min. She required 5 L/min of oxygen via facemask to maintain Spo2>98%. Coarse crackles were heard over both lung fields. X-ray demonstrated mild cardiomegaly with bilateral pulmonary congestion (Figure 1). Electrocardiography, which had been within normal limits 2 years previously, showed changes resembling acute myocardial infarction (Figure I in the online-only Data Supplement). Echocardiography showed global hypokinesis in the left ventricular (LV) wall, and regional akinesis in the septum and inferoseptal wall. Coronary artery angiography revealed no significant stenosis or intracoronary plaque rupture. Her serum creatinine kinase level was high at 2558 IU/L. CMR was performed on day 7. Cine-CMR showed global hypokinesis in …