A first-degree family history in lone atrial fibrillation patients

BackgroundAtrial fibrillation (AF) may be due to an inherited trait, particularly in lone AF patients. A family history of AF in lone AF patients has not previously been compared with a family history of patients with AF and established risk factors (non–lone AF).ObjectiveThe purpose of this study was to compare the frequency of having a first-degree relative with AF in lone and non–lone AF patients.MethodsWe performed a case-control study of consecutive subjects presenting to a single electrophysiology laboratory. A convenience sample of subjects with no known arrhythmias was also enrolled.ResultsFour hundred twenty-nine subjects were enrolled: 136 had AF (54 with lone AF), 84 had atrial flutter, 158 had other supraventricular arrhythmias, and 51 had no known arrhythmias. Significantly more subjects with AF reported a first-degree family history of AF compared with the remainder of the cohort (25% vs. 5%; P <.001). In multivariable analysis adjusting for potential confounders, AF patients had a 6-fold greater odds of having a family member with AF (95% confidence interval [CI] 2.93–12.7; P <.001). Lone AF patients had a first-degree family member with AF substantially more often than those with non–lone AF (41% vs. 14%; P <.001). After adjusting for potential confounders, lone AF patients remained significantly more likely than other AF patients to have a first-degree relative with AF (OR 7.2; 95% CI 2.1–24.7; P = .002).ConclusionLone AF patients have a first-degree family member with AF substantially more often than other AF patients. This suggests that an inherited trait may be particularly important in this subgroup of patients.