Objective: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia associated with substantial morbidity and significant mortality. The familial aggregation of AF elsewhere in the world has been documented. This investigation sought to evaluate familial aggregation of lone AF in the Chinese population.
Methods: The study population included 382 unrelated patients with lone AF, and their 6,856 relatives. The controls were 15,507 age-sex-matched individuals from the general population. The prevalence of AF in each class of relatives was compared to that in each subgroup of the age- and sex- comparable control individuals.
Results: The relatives of patients with lone AF had a significantly increased risk of the arrhythmia as compared to the general population. The relative risk (95% confidence intervals) of AF for relatives compared to the general population was: 37.36 (12.71-109.9) for sons, 166.6 (22.06-1258) for daughters, 27.39 (14.63-51.26) for brothers, 24.49 (14.01-42.83) for sisters, 4.87 (2.84-8.35) for mothers, and 4.78 (3.00-7.59) for fathers.
Conclusion: These findings provide evidence suggesting that there is a significant familial aggregation of lone AF among Chinese families and a Mendelian genetic component involved in the pathogenesis of this prevalent disorder.