More than two million Americans live with a serious heart condition called atrial fibrillation. These patients are five-times more likely to have a stroke. NCH Cardiac Electrophysiologist Dinesh Sharma, MD, discusses the signs of atrial fibrillation, its relation to strokes and treatment with the WATCHMAN left atrial appendage closure device. Most strokes associated with AF are thought to be due to migration of blood clots that form in the left atrial appendage. Typically patients with AF take blood thinning medications to prevent these clots from forming in the heart. The WATCHMAN device is designed to capture any clots that may form in the appendage potentially reducing the risk of stroke and eliminating the need for long-term use of blood thinning medications.