Association of the Clinical and Genetic Factors With Superior Vena Cava Arrhythmogenicity in Atrial Fibrillation

BACKGROUND: Atrial fibrillation (AF) can be initiated from arrhythmogenic foci within the muscular sleeves that extend not only into the pulmonary veins but also into both vena cavae. The superior vena cava (SVC) is a key target site for catheter ablation. Patients with SVC-derived AF often lack the clinical risk factors of AF. METHODS AND RESULTS: We conducted a meta-analysis of the clinical and genetic factors of 2,170 AF patients with and without SVC arrhythmogenicity. In agreement with previous reports, the left atrial diameter was smaller in AF patients with SVC arrhythmogenicity. Among 6 variants identified in a previous genome-wide association study in Japanese patients, rs2634073 and rs6584555 were associated with SVC arrhythmogenicity. This finding was confirmed in our meta-analysis using independent cohorts. We also found that SVC arrhythmogenicity was conditionally dependent on age, body mass index, and left ventricular ejection fraction. CONCLUSIONS: Both clinical and genetic factors are associated with SVC arrhythmogenicity.