Having a first-degree relative with atrial fibrillation -- abnormal heart rhythm -- may increase one's risk for the disorder, a U.S. researcher says.
Study leader Dr. Steven Lubitz of the Cardiovascular Research Center at Massachusetts General Hospital says the occurrence of atrial fibrillation in first-degree relatives was associated with atrial fibrillation risk after adjustment for established risk factors and
related genetic variants.
Lubitz and colleagues examined the heritability of atrial fibrillation among Framingham Heart Study participants. Original and offspring
participants were at least 30 years of age, free of atrial fibrillation at the beginning of the study begun in 1948, and had at least one
parent or sibling enrolled in the study.
The 4,421 participants -- average age of 54 years and 54 percent women -- were followed up through December 2007.
"A heritable component underlying atrial fibrillation has been well demonstrated, and it is now evident that genetic variants are
associated with atrial fibrillation risk. However, the contribution of familial atrial fibrillation -- defined in this study as the occurrence of atrial fibrillation in a first-degree relative prior to an examination commencing an eight-year follow-up period -- to predicting new-onset atrial fibrillation remains unknown," the investigators say in a statement. "Future efforts should attempt to discern the factors that mediate the association between familial atrial fibrillation and atrial fibrillation risk."
The study, scheduled to be published in the Journal of the American Medical Association, is also being presented at the meeting of the
American Heart Association in Chicago.