Lone atrial fibrillation is associated with pectus excavatum

BACKGROUND Pectus excavatum is a skeletal abnormality that may have cardiac manifestations. OBJECTIVE To determine whether pectus excavatum is associated with lone atrial fibrillation (AF). METHODS The pectus severity index (PSI) is the ratio of the lateral diameter of the chest to the distance between the sternum and the spine on computed tomography scan. A normal PSI is <= 2.5 whereas patients with severe pectus excavatum have a PSI >3.25. We calculated the PSI of 220 consecutive patients with AF who underwent radiofrequency catheter ablation from September 2008 to 2012 and compared this to the PSI of 225 controls without a history of AF undergoing chest computed tomography. RESULTS Mean PSI was higher in patients with Lone AF (2.72 +/- 0.07) compared to patients with nonlone AF (2.25 +/- 0.03) or controls (2.26 +/- 0.03) (P < .001). The Likelihood of mild, moderate, or severe pectus excavatum was higher in patients with Lone AF compared to patients with nonlone AF and controls (P < .001). Patients with lone AF were more than 5 times as likely to have severe pectus excavatum compared to patients with nonlone AF or controls (P < .001) even after adjustment for potential confounders. CONCLUSIONS Nearly two-thirds of the patients with lone AF have at Least mild pectus excavatum and 17% have severe pectus, which is significantly higher than in patients with nonlone AF or controls. This association suggests a potential genetic or mechanical abnormality may be common to the 2 disorders. Our study may provide insight into the pathogenesis of lone AF.