BALTIMORE, Dec. 29 (UPI) -- DNA sequence variations associated with abnormal heart rhythms that can cause heart damage and sudden death have been identified, a U.S. researcher says.
An international team studying almost 50,000 people worldwide found variants in 22 locations across the human genome that can affect the QRS interval, a measure of electrical rhythms in the heart's lower chambers, known as the ventricles, HealthDay News reported this week.
The QRS interval can be easily measured on an electrocardiogram.
A prolonged QRS interval has been associated with increased risk for heart problems and sudden cardiac death, researchers say.
DNA variations in two side-by-side genes that regulate signals that activate heart contractions were discovered, they said.
One of those genes had not been suspected of playing any role in cardiac electrical activity at all, the researchers noted.
"The size of this study really gave us the power to identify many genes not previously suspected to play a role in heart conduction," Dan Arking, an assistant professor at the Johns Hopkins University School of Medicine, said.
