Glucocorticoid-sensitive Paroxysmal Atrial Fibrillation, Sick Sinus Syndrome, and Mitral Regurgitation in a Patient with Malignant Rheumatoid Vasculitis

An 80-year-old woman with rheumatoid arthritis presented with chest pain. Clinical examination revealed new-onset paroxysmal atrial fibrillation with symptomatic sinus pauses and worsening mitral regurgitation, which were both resistant to conventional therapies. Based on her skin lesions, an increase in pleural and pericardial effusion, possible myocardial involvement, and a positive finding for immune complex testing, rheumatoid vasculitis was diagnosed. Subsequent glucocorticoid therapy suppressed systemic inflammation, resulting in structural, functional, and electrical reverse remodeling of the left atrium with complete remission of atrial arrhythmias and also an improvement of mitral regurgitation. This case highlights the importance of evaluating the underlying disease activity in a case of de novo paroxysmal atrial fibrillation associated with systemic autoimmune disease.