Size may matter when it comes to a safe and steady heart. New research shows tall people may be more likely to suffer from the most common form of irregular heartbeat, known as atrial fibrillation (search).

The study shows tall men and women with heart failure had a 60 percent higher risk of atrial fibrillation than short men and women with the same risk factors.

Atrial fibrillation is an irregular heart rhythm that causes the heart to pump blood less efficiently.

The condition is usually not life threatening, but if untreated it can increase the risk of stroke and heart attack. People with heart failure whose hearts already pump blood ineffectively are particularly vulnerable to developing atrial fibrillation.

The results of the study were presented at the American Heart Association's Scientific Sessions 2004.

Height Linked to Atrial Fibrillation Risk

Researchers say the size of the heart chamber increases proportionately with height, and the ratio of heart size to the electrical impulses that regulate heartbeat may be a predictor of atrial fibrillation risk.

In their study, researchers looked at the relationship between height and atrial fibrillation among 16,730 people with heart failure.

Researchers divided the men and women into categories according to their height and found the prevalence of atrial fibrillation increased with each increasing height category, regardless of other risk factors such as body mass index (a measure of weight in relation to height), age, sex, and severity of heart failure.

Men and women in the tallest height categories (over 5'11" for men and 5'5" for women) were 60 person more like likely to have atrial fibrillation than those in the shortest category (under 5'7" for men and 5'1" for women).

Researchers say the results suggest that tall stature may be a "potent predictor" of atrial fibrillation risk in people with heart failure. They say taller stature may be one of the reasons men have a higher prevalence of atrial fibrillation than women.

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: American Heart Association Scientific Sessions 2004, New Orleans, Nov. 7-10, 2004. News release, American Heart Association.