Intermittent complete atrioventricular block in a 20-year-old woman with cardiac sarcoidosis: a case report

BACKGROUND: Atrioventricular conduction disturbance may rarely be caused by cardiac involvement of sarcoidosis. CASE SUMMARY: A 20-year-old Caucasian female with exertional dyspnoea was admitted to the hospital. Electrocardiogram revealed intermittent complete atrioventricular block with ventricular escape rhythm. Laboratory findings indicated no obvious cause for the complete heart block, and echocardiography showed no abnormalities with normal systolic left ventricular function. However, in gadolinium-enhanced cardiovascular magnetic resonance imaging, a mass at the basal septum with high intensity of T2-weighted signal was found, and 18-fluorodeoxyglucose positron emission tomography revealed severe enhancement in this area and in the mediastinal lymph nodes. The diagnosis of cardiac sarcoidosis was established by the detection of non-caseating epithelioid granulomas in the endobronchial lymph node biopsy. Corticosteroid therapy with oral administration of 30 mg prednisolone was initiated, and complete recovery of atrioventricular block was observed within several weeks, obviating the need for permanent pacemaker implantation. DISCUSSION: Cardiac sarcoidosis can cause complete atrioventricular block and should always be considered, especially in younger patients. Early diagnosis and initiation of corticosteroid therapy may lead to complete recovery of conduction system without the need for permanent pacemaker implantation.