P325 CARDIAC SARCOIDOSIS PRESENTING WITH ATRIOVENTRICULAR BLOCK AND SUBSEQUENT CARDIAC ARREST: A CASE REPORT

Abstract A 53–year–old male patient with no significant past medical history and no familiar history for cardiac diseases presented to the emergency department for asymptomatic bradycardia. The ECG showed complete atrioventricular block in the absence of pathological findings on the echocardiogram and no coronary lesions were found on coronary angiography. The patient underwent pacemaker (PM) implantation. A few months later the patient suffered from cardiac arrest in sustained ventricular tachycardia, effectively treated with DC shock. The echocardiogram showed mild right ventricular dilation and dysfunction with regional wall motion abnormalities, especially in the subtricuspid site. Cardiac magnetic resonance imaging (MRI) showed focal areas of delayed enhancement with a non–ischaemic pattern and distribution with a hook sign, highly suggestive of cardiac sarcoidosis. FDG PET showed cardiac, hepatic, splenic, and lymph nodal uptake. In the suspicion of systemic sarcoidosis, an hepatic biopsy was performed, being the liver the most accessible site. The histological examination showed the presence of non–caseating granulomas. Therefore, a diagnosis of Systemic Sarcoidosis (SS) with Cardiac involvement was made and the PM was upgraded to CRT–D in secondary prevention. The patient was discharged with cortisone therapy. Three months after discharge, a new total body PET–CT scan was performed and showed, in comparison to the previous one, the absence of areas of significant hypermetabolism in the cardiac, hepatic and bone fields. Cardiac sarcoidosis (CS) is a rare inflammatory granulomatous myocardial disease of unknown etiology that should be suspected in young patients with atrioventricular conduction disturbances and complex ventricular arrhythmias. The diagnostic approach is challenging: imaging techniques (MRI, PET) can be suggestive of CS but biopsy with histological demonstration of the non–caseous granuloma is mandatory. Endomyocardial biopsy (which has suboptimal sensitivity due to focal lesion) could be avoided if there is a more accessible and less invasive extracardiac site for biopsy. Early diagnosis relies on multidisciplinary collaboration and is essential for staging and long–term management of the disease and prevention of sudden cardiac death. Cortisone therapy remains the mainstay of treatment.