Myocarditis of mixed connective tissue disease: favourable outcome after intravenous pulsed cyclophosphamide

A 30-year-old woman with mixed connective tissue disease was admitted with Wernicke's aphasia and progressive dyspnoea with chest pain. Multiple brain infarcts on a computed tomographic scan were compatible with a thromboembolic aetiology. Echocardiography showed marked hypokinesia of the posterior wall, biventricular dilatation and a decreased left-ventricle ejection fraction (40%). A diagnosis of myocarditis was made on myocardial biopsies disclosing interstitial lymphocytic infiltrates and myocardial fibre necrosis. A treatment with steroids and monthly pulsed cyclophosphamide was introduced. The heart function rapidly improved as assessed by a left-ventricle ejection fraction of 55% and remained stable 17 months thereafter.