Supraventricular arrhythmias in patients with cardiac sarcoidosis: Prevalence, predictors, and clinical implications

Background: Cardiac sarcoidosis (CS) is known to be associated with congestive heart failure, conduction disorders, and tachyarrhythmias. Ventricular arrhythmias are the most feared cardiac manifestation because they often are unpredictable, may be the first manifestation of the disease, and may be fatal. The propensity for the development of supraventricular arrhythmias (SVAs) in patients with CS has not been described. The aim of this study was to assess the prevalence as well as the predictors of SVA. Methods: We retrospectively investigated 100 patients with biopsy specimen-proven systemic sarcoidosis and evidence of cardiac involvement (defined by cardiac biopsy specimen, PET scan, or cardiac MRI). The mean follow-up was 5.8 ± 3.6 years. ECG, Holter monitoring, implantable cardioverter defibrillator interrogations, or electrophysiology studies were used to document SVA. Echocardiographic data, demographics, and extracardiac involvement were recorded, and univariate and Poisson regressions were performed to compare characteristics of patients with and without documented SVA. Results: The prevalence of SVA was 32%, and atrial fibrillation was the most common arrhythmia, comprising 18% of the total burden, followed by atrial tachycardias (7%), atrial flutter (5%), and other supraventricular tachycardias (2%). Of the patients with SVA, 96% were symptomatic. Left atrial enlargement (LAE) was more frequent in the group with SVA, with an incidence of 267.8 per 1,000 person-years, and it significantly increased the likelihood of SVA on multivariate analysis (risk ratio, 6.12; 95% CI, 2.19-17.11). Diastolic dysfunction, systemic hypertension, and right atrial enlargement were predictors of SVA on univariate analysis. Left ventricular hypertrophy, right ventricular dysfunction, tricuspid valve disease, pulmonary hypertension, and pulmonary sarcoidosis were not associated with SVA on univariate analysis. Conclusions: The study systematically evaluated the frequency of SVA in a large number of patients with CS. SVA in patients with CS is frequent and associated with symptoms. LAE was clearly associated with the development of SVA in this patient population. The extent to which LAE predicts the occurrence of SVA in larger, more diverse CS populations should be evaluated prospectively.