Analysis of data from a registry of patients with left ventricular dysfunction indicates that height is an independent risk factor for an arrhythmia of the upper chambers of the heart, according to a new study in the April 18, 2006, issue of the Journal of the American College of Cardiology.
"Tall stature is a potent risk for the development of atrial fibrillation and is independent of other clinical risk factors. Indeed, the male predominance of atrial fibrillation appears to be explained by the difference in height between men and women," said Jonathan J. Langberg, M.D. from Emory University in Atlanta, Georgia.
Atrial fibrillation is the most common sustained cardiac arrhythmia. During an episode, the upper chambers of the heart flutter instead of pumping blood effectively. The incidence increases as people age, with a prevalence of more than 5 percent in patients over the age of 65 years.
The size of the left atrium of the heart is known to be associated with atrial fibrillation, so the researchers wanted to see if bigger people have a higher risk of atrial fibrillation.
"It is well known that small animals do not develop atrial fibrillation, while those larger than humans, particularly horses, seem to be quite susceptible. I also encountered a string of very tall patients, most of whom were former basketball players, with lone atrial fibrillation," Dr. Langberg said.
The researchers, including first author Ibrahim R. Hanna, M.D., reviewed data on 25,268 enrolled in the ADVANCENT registry. ADVANCENT is a prospective, longitudinal, multicenter, observational registry designed to collect and report data on the histories, diagnostics, therapies, and interventions for patients with left ventricular dysfunction (ejection fraction < 40 percent). They separated the patients by height into four groups each for men and women and then compared atrial fibrillation rates.