Whites at Highest Risk for Irregular Heart Rhythm, Study Finds

Whites are more likely than other racial or ethnic groups in the United States to develop a common heart rhythm disorder called atrial fibrillation, a new study finds.

The condition -- caused by a problem in the heart's electrical system -- can cause symptoms such as palpitations, shortness of breath and dizziness. It can also raise the risk of stroke, heart attack and heart failure. Research shows that people older than 40 have a 26 percent lifetime risk of developing atrial fibrillation.

In this study, investigators analyzed data collected from 14 million patients in California between 2005 and 2009, and found that the risk of atrial fibrillation in whites was 16 percent higher than in blacks and 22 percent higher than in Hispanics and Asian Americans.

"We found that consistently, every other race had a statistically significant lower risk of atrial fibrillation compared to whites. So this suggests that white race is itself a risk factor for atrial fibrillation," study senior author Dr. Gregory Marcus, an associate professor of medicine in the cardiology division at the University of California, San Francisco (UCSF), said in a university news release.

The study was published online Oct. 8 in Circulation and will appear in the journal's Nov. 12 print issue.

Previous research found that blacks are at lower risk for atrial fibrillation than whites, even though they have more risk factors for the condition. This raised the question as to whether blacks were protected or whites were at increased risk, which led to this new study.

Study first author Dr. Thomas Dewland, a cardiac electrophysiology fellow in UCSF's cardiology division, said the findings suggest "there is some characteristic unique to whites that increases the likelihood of this abnormal heart rhythm."

According to Marcus, "there may be a gene, or a set of genes, in European ancestry or some important behavior or environmental exposure in whites that increases the risk for atrial fibrillation."

However, he added, "based on several analyses performed in the study, the risk is not related to existing cardiac conditions like high blood pressure or existing heart disease."

More information

The U.S. National Heart, Lung, and Blood Institute has more about atrial fibrillation.