Usefulness of cardiac magnetic resonance imaging in the diagnosis of cardiac myocarditis revealed by complete atrioventricular block

Abstract

MOTS CLES Bloc atrioventriculaire A previously healthy 37-year-old man was admitted to our hospital for recurrent syncope. An electrocardiogram showed complete atrioventricular block (Fig. 1A). Medical history, clinical examination, echocardiography, chest X-ray (Fig. 1B), coronary arteriography, biological samples (including calcaemia, lyme serology, angiotensin enzyme blood concentration, antineutrophil cytoplasmic antibody and antinuclear antibody tests) were all unremarkable. Cardiac magnetic resonance (CMR) imaging showed extensive subepicardial enhancement in the basilar anterior, inferoposterior and septal ventricular walls (arrows, Fig. 1C and D). These findings were consistent with fibrotic lesions related to subacute or chronic myocarditis. A computed tomography scan demonstrated evidence of micronodular pulmonary infiltration (Fig. 1E) and spleen hypodense nodular lesions (Fig. 1F). Salivary gland and bronchial biopsies were normal. Despite the absence of non-necrotizing granulomas in the biopsies, our internal medicine team considered that the overall clinical pattern was