Diagnosis of cardiac sarcoidosis in patients presenting with cardiac arrest or life-threatening arrhythmias

ObjectiveCardiac sarcoidosis (CS) may present with cardiac arrest or life-threatening arrhythmias. There are limited data on this subgroup of patients with CS. Advanced imaging including cardiovascular magnetic resonance (CMR) and cardiac 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) are used for diagnosis. This study aimed to describe advanced imaging patterns suggestive of CS among patients presenting with cardiac arrest or life-threatening arrhythmias.MethodsAn imaging database of a CS referral centre (Royal Brompton Hospital, London) was screened for patients presenting with cardiac arrest or life-threatening arrhythmias and having imaging features of suspected CS. Patients diagnosed with definite or probable/possible CS were included.ResultsStudy population included 60 patients (median age 49 years) with male predominance (76.7%). The left ventricle was usually non-dilated with mildly reduced ejection fraction (53.4±14.8%). CMR studies showed extensive late gadolinium enhancement (LGE) with 5 (4–8) myocardial segments per patient affected; the right ventricular (RV) side of the septum (28/45) and basal anteroseptum (28/45) were most frequently involved. Myocardial inflammation by FDG-PET was detected in 45 out of 58 patients vs 11 out of 33 patients with oedema imaging available on CMR. When PET was treated as reference to detect myocardial inflammation, CMR oedema imaging was 33.3% sensitive and 77% specific.ConclusionsIn patients with CS presenting with cardiac arrest or life-threatening arrhythmias, LGE was located in areas where the cardiac conduction system travels (basal anteroseptal wall and RV side of the septum). While CMR was the imaging technique that raised possibility of cardiac scarring, oedema imaging had low sensitivity to detect myocardial inflammation compared with FDG-PET.