A 48-year-old man with no medical history presented with dyspnoea on slight exertion and malleolar oedema of 15 days' duration. Examination showed bibasal crackles and blood tests showed 11,600 leukocytes with 78.5% segmented, 13.4% lymphocytes and 7.2% monocytes, in addition to normal biomarkers. The electrocardiogram showed previously known left bundle branch block. Chest X-ray revealed cardiomegaly and bilateral interstitial infiltrates and chest CT showed diffuse interstitial thickening over "ground glass" images ("crazy paving" pattern). Given the findings suggestive of interstitial pneumonitis, it was decided not to initiate antibiotic therapy. Transthoracic echocardiography revealed ventricular dilatation with severe systolic dysfunction, so he was transferred to cardiology. Coronary angiography showed severe lesions in the distal anterior descending, proximal circumflex and acute marginal arteries, which did not justify myocardial dysfunction. Cardiac MRI was performed one month after symptom onset and showed anterolateral hyperintensity with late subepicardial enhancement, left ventricular dilatation and LVEF of 13%, compatible with subacute myocarditis. Anti-CMV IgM and IgG antibodies and anti-CMV PCR were positive, so treatment with oral valganciclovir was started for two weeks. He progressed satisfactorily and three months later remained clinically stable, with baseline NYHA class II dyspnoea and LVEF of 45% according to control echocardiography.
