CONGRESS ABSTRACT

CASE REPORT A 45-year-old man with no prior cardiac history presented with exertional angina and dyspnoea. EKG showed first-degree AV block (AVB I) and right bundle branch block (RBBB). A stress test revealed a 2:1 AVB without inducible ischemia. Later he was admitted for NSTEMI, the peak troponin level was 1065 ng/L and echocardiography revealed akinesia of the inferior wall. Coronary angiography showed a localized critical stenosis in the mid-distal right coronary artery, treated successfully, with otherwise clear arteries. Advanced AVB persisted for over five days post-revascularization. After excluding infectious and infiltrative causes, a pacemaker was implanted. Post-discharge MRI showed biventricular dysfunction (LVEF 36%, RVEF 28%) and extensive patchy intramyocardial and subepicardial late gadolinium enhancement (LGE) involving most of the basal segments of LV and RV with sparing of inferolateral wall, involving also the true apex. Accordingly, PET-CT demonstrated FDG accumulation consistent with the MRI locations without sings of extracardiac involvement. To confirm a definitive diagnosis of isolated cardiac sarcoidosis, endomyocardial biopsy was performed, which revealed caseating granulomas.  DISCUSSION This clinical case is notable for its unusual presentation, initially resembling acute coronary syndrome but revealing inconsistencies. The atrioventricular block observed is not justified by the extent or location of the coronary artery disease, which persisted despite percutaneous treatment. Moreover, the axiom of a young patient with advanced AV block should always raise suspicion of a non-ischemic aetiology, even if common sarcoidosis associated biomarkers (ACE and 24-hour urinary calcium) are negative, due to their low sensitivity and specificity (22-86% and 54-95%, respectively). Although sarcoidosis is a rare disease, with a global prevalence of 140-160 cases per 100,000 in Northern European countries, it is responsible for 30% of AVB in young patients. Clinical and instrumental red flags such as advanced AVB in young patients, RBBB, extensive biventricular LGE wildly affecting the RV as well, must warrant suspicion. Comprehensive evaluation with advanced imaging techniques, particularly MRI and PET-CT, is essential for accurate diagnosis which is then confirmed solely through an histological sample.