A Systematic Review of a Long-forgotten Cause of Atrial Fibrillation and Stroke: Cor Triatriatum

Cor triatriatum is a rare congenital cardiac condition characterized by the division of one atrium into two chambers by a fibromuscular membrane, resulting in three atrial chambers. The goal of this study was to determine the associations of cor triatriatum with cyanosis, atrial fibrillation (AF), and stroke. MEDLINE (PubMed, Ovid), Embase, and Cochrane databases were searched on April 25, 2019, for relevant articles on cor triatriatum. After initial screening and removal of duplicates, 235 articles were selected. Data were extracted from these articles, including types, presentations, diagnostic findings, management, and outcomes of patients with cor triatriatum. Approximately 83% of patients with cor triatriatum had cor triatriatum sinistrum (CTS) and 17% had cor triatriatum dextrum (CTD). The mean age of all patients was 29±23 years. Mean ages at diagnosis differed significantly in patients with CTS and CTD (31±23 years vs. 21±20 years, p=0.02). CTS showed a significantly greater association with AF (14.65% vs. 12.5%, p=0.036) and had a substantially higher risk of stroke (7.9% vs. 5.0%, p=0.04) than CTD. CTS also had a numerically higher association with atrial septal defects (15.13% vs. 15.6%), but this difference was not statistically significant (p=0.89). In contrast, cyanosis at presentation was significantly more frequent in patients with CTD than CTS (5.5% vs. 5.3%, p=0.05). Management did not differ significantly between these groups (p=0.29). The overall mortality rate was 16%, with no significant difference between patients with CTS and CTD (p=0.33). The higher likelihood of AF and stroke in CTS than in CTD patients warrants treatment of the former with anticoagulation agents, irrespective of their CHA₂DS₂-VASc scores (congestive heart failure, hypertension, age, diabetes mellitus, stroke, vascular disease, age, sex category). Patients with CTS usually present at an older age due to their lower risk of cyanosis and asymptomatic AF.