[Clinical characteristics of arrhythmia-onset sarcoidosis cases]

Objective: To describe the clinical characteristics of sarcoidosis patients with arrhythmia as the primary or main manifestation. Methods: We conducted a retrospective analysis of arrhythmia-onset sarcoidosis cases between January 2017 and December 2020. Their clinical manifestations, radiological features, treatment and prognosis were reviewed and analyzed. Results: This study consisted of 3 females and 1 male, with a mean age of 51 years (range from 42 to 58 years old). Arrhythmia was the first or main clinical manifestation for all 4 cases, involving Ⅲ° atrioventricular block (AVB) (n=1), Ⅱ° type Ⅱ AVB (n=1), and frequent ventricular premature beats and short array ventricular tachycardia (n=2). Three cases were diagnosed with respiratory sarcoidosis simultaneously during the diagnostic evaluation for arrhythmia. One case was diagnosed with sarcoidosis because of abnormal chest CT images due to cervical lymph node enlargement 5 years after arrhythmia. All 4 cases were confirmed as presenting epithelioid cell granulomatous inflammation by bronchoscopic biopsies. Late gadolinium enhancement with cardiac magnetic resonance (LGE-CMR) imaging was arranged for two cases. Both of them had typical imaging findings of cardiac sarcoidosis. Three cases were confirmed of cardiac involvement through positron emission computed tomography (PET)-CT. None of the enrolled four cases were arranged with endomyocardial biopsy. All four cases were improved with oral corticosteroids, immunosuppressants and anti-arrhythmic medications. Two cases underwent cardiac pacemaker implantation. Conclusions: The possibility of cardiac sarcoidosis should be considered in middle-aged and elderly patients with unexplained high-degree AVB or ventricular arrhythmia. Chest CT is recommended for routine screening for those cases. LGE-CMR and/or PET-CT is recommended for them to confirm the diagnosis of cardiac sarcoidosis. Corticosteroids and immunosuppressants are effective for these patients.