Abstract 14466: Recurrent Heart Block Due to Cardiac Sarcoidosis in a Patient With Interrupted Glucocorticoid Therapy

Abstract

Background: Cardiac involvement is a major cause for mortality in patients with systemic sarcoidosis. Atrioventricular (AV) block caused by inflammation involving the conduction system is one of the major manifestations of cardiac involvement. The mainstay of management is immunosuppressive therapy and device implantation if high degree AV block is present. However, there is lack of evidence regarding the appropriate dose and duration of corticosteroids in the treatment of cardiac sarcoidosis. Case summary: We describe the case of a 62-year-old man who presented with symptoms of dyspnea and bradycardia and was found to be in second degree AV block type II. Computed tomography of the chest showed hilar lymphadenopathy. Echocardiography revealed reduced systolic function (LVEF of 35-40%). A FDG-PET scan showed hypermetabolic activity of the interventricular septum and pericardium consistent with sarcoidosis. Bronchoscopy with BAL and EUS biopsies revealed necrotizing granulomas consistent with pulmonary sarcoidosis. ICD/pacemaker implantation was discussed; however the patient deferred and ultimately underwent Boston Scientific ILR placement to monitor for arrhythmias. He was started on methotrexate and prednisone with improvement in heart rate from 2:1 AV block (rates 30's) to sinus rhythm with rates in the 60's. Subsequent stress testing demonstrated improvement in heart rate with exercise to 113 bpm. His AV block had decreased in frequency per Implantable loop recorder (ILR) monitoring. A month later, the patient stopped taking prednisone and methotrexate and developed a symptomatic recurrence of 2:1 AV block. He then underwent dual chamber pacemaker implantation with ILR explant. Discussion: This case highlights the importance of maintaining and educating patients about long term immunosuppressive treatment in cardiac sarcoidosis to prevent recurrence of conduction abnormalities. The initial dose for those receiving prednisone is typically 40mg daily, while for those patients receiving an additional immunosuppressive agent, the initial dose can be 20mg daily. Based on response to treatment after 1 to 3 months, immunosuppressive therapy should be continued for an additional 9 to 12 months.