People with a first-degree relative who has/had atrial fibrillation have a 40% higher risk of developing it themselves, compared to others, researchers from Massachusetts General Hospital wrote in JAMA (Journal of the American Medical Association). A first degree relative is a biological parent, sibling or offspring; somebody who shares about 50% of their genes with a particular member of a family.
Our hearts have two upper chambers (left atrium and right atrium) and two lower chambers (left ventricle and right ventricle). When the atria (plural of atrium) contract too rapidly and irregularly, the patient has atrial fibrillation (AF). In other words, the contractions of the atria are not synchronized with the contractions of the ventricles, causing poor blood flow to the body.
The authors wrote:
- "A heritable component underlying atrial fibrillation has been well demonstrated, and it is now evident that genetic variants are associated with AF risk."
Steven A. Lubitz, M.D., M.P.H., and team looked at a possible link between AF occurrence in a first-degree relative and AF risk, they hypothesized that by considering the genetic association, the prediction of new-onset AF would improve.
They gathered information from the Framingham Heart Study, consisting of 4,421 patients, 54% female, average age 54. This cohort study began in 1948 and continued through 2007. All original participants, as well as offspring participants had no AF when they entered the study. The researchers specifically examined the period 1968-2007.
Highlighted below is what they found:
- Familial atrial fibrillation occurred in 26.8% of participants; 1,185 of them
- Premature atrial Fibrillation occurred in 7.9% of participants; 351 of them. Premature refers to onset starting up to the age of 65 years
- Familial AF was present in 2,393 examinations. Sources included 1,163 fathers, 1,068 mothers and 404 siblings.
The authors concluded:
- "Future efforts should attempt to discern the factors that mediate the association between familial AF and AF risk, further explore the relationships between premature familial AF and risk prediction, and determine whether incorporating genetic variants into an AF prediction model enhances its performance."
Steven A. Lubitz, MD, MPH; Xiaoyan Yin, PhD; João D. Fontes, MD; Jared W. Magnani, MD; Michiel Rienstra, MD, PhD; Manju Pai, MD; Mark L. Villalon, MD; Ramachandran S. Vasan, MD; Michael J. Pencina, PhD; Daniel Levy, MD; Martin G. Larson, ScD; Patrick T. Ellinor, MD, PhD; Emelia J. Benjamin, MD, ScM
JAMA. Published online November 13, 2010. doi:10.1001/jama.2010.1690
Written by Christian Nordqvist