(WUSA) --  We frequently talk about heart attacks and stroke, and their risk factors and symptoms. But Tuesday we're focusing on another problem many people have never heard of: Atrial Fibrillation, also known as A-Fib.

Doctor Hugh Calkins with the Heart Rhythm Society is also a professor of medicine at Johns Hopkins Hospital. He talked to us about how to spot signs of trouble and what you can do to help a relative experiencing problems.