Atrial fibrillation, or “a-fib,” is a common heart problem that can greatly increase the risk of stroke, as two Upstate nurses explain. A heart that is in atrial fibrillation is beating too fast, too slow or irregularly, which might allow blood to pool and clot instead of being pumped normally, say Lorraine “Lorrie” Langdon (at right), coordinator of the Heart Failure Program, and Michelle Vallelunga (at left), data coordinator of the Comprehensive Stroke Center at Upstate. Those clots can travel to the brain and cause a stroke. The nurses go over risk factors and how atrial fibrillation is diagnosed and treated, plus what to do if you think someone is experiencing atrial fibrillation or a stroke.