TUESDAY, April 16 (HealthDay News) -- A common test that records the electrical activity of the heart can identify a potentially serious heart problem previously thought to pose no threat, a new study says.

The condition, called "left anterior fascicular block" (LAFB), involves scarring in a section of the hearts' left ventricle (pumping chamber). People with the condition may be at higher risk of heart failure, sudden cardiac death or a dangerous heart rhythm disorder called atrial fibrillation, the new study found.

In this study, researchers analyzed data from more than 1,600 people older than age 65 who were followed for 16 years. People with heart failure, high blood pressure, diabetes or a history of heart attack were not included in the study.

Electrocardiogram (ECG) was used to record the electrical activity of the participants' hearts.

"We then compared those with LAFB to those with a normal electrocardiogram, we found that those who had LAFB indeed had a higher risk of atrial fibrillation, congestive heart failure and death," senior study author Dr. Gregory Marcus, an electrophysiologist in the cardiology division at the University of California, San Francisco and an associate professor in residence with the UCSF School of Medicine, said in a university news release.

The study appears in the April 17 issue of the Journal of the American Medical Association.

Rates of LAFB are unknown and there is no treatment for the condition, Marcus noted. He said the findings could open a new area of research in cardiology.

"This study may suggest that LAFB, even in the absence of known high blood pressure or diabetes, should be thought of as a cardiovascular risk factor," Marcus said. "Those patients with LAFB perhaps should be considered the same as someone with an established cardiovascular risk factors."

More information

Find out more about the electrocardiogram at the U.S. National Library of Medicine.