More than 33 million people around the world -- 0.5 percent of the population -- have the most common cause of irregular heartbeat, a condition called atrial fibrillation, according to a new study.

The Circulation study, the first to look at the prevalence of atrial fibrillation, is based on data from population-based studies published between 1980 and 2010 on atrial fibrillation. A team of researchers from Cedars-Sinai Heart Institute and the Institute for Health Metrics and Evaluation at the University of Washington analyzed the data to find that the prevalence of the condition has increased from 1990 to 2010, going from 570 men out of every 100,000 to 596 men out of every 100,000. For women, the prevalence increased from 360 out of every 100,000 women in 1990, to 373 out of every 100,000 women in 2010.

"Atrial fibrillation has a huge cost in every sense of the word," study researcher Dr. Sumeet Chugh, M.D., the associate director of the Cedars-Sinai Heart Institute, said in a statement. "It can lead to stroke, hospitalization, as well as lost productivity. Our findings indicate that atrial fibrillation is on the rise around the world and it's a huge public health burden."

Chugh and colleagues also found that new cases of atrial fibrillation increased over the last three decades, with there being 61 new cases of atrial fibrillation in men for every 100,000 people in 1990, to 78 new cases in men for every 100,000 people in 2010. For women, it was 43 new cases of atrial fibrillation for every 100,000 people in 1990, compared with 60 new cases in women for every 100,000 people in 2010.

Atrial fibrillation occurs when the atria (the upper chamber of the heart) doesn't beat properly, and is out of sync with the two ventricles (the lower chambers) of the heart. While the condition itself is usually not dangerous, the Mayo Clinic noted that people with the condition may sometimes experience symptoms of heart palpitations, decreased blood pressure, shortness of breath and chest pain. Complications can also occur, such as stroke and heart failure.