Atrial fibrillation puts you at higher risk for having a stroke because blood clots can be formed in certain areas of the heart. Typically a blood thinner is used to reduce the risk. Patients who cannot tolerate long-term blood thinners or a wish not to take them can instead have a Watchman device implanted in their heart. This device is placed though a catheter from the groin and does not need open heart surgery. In most cases, once the device is implanted we do not need to continue with long-term blood thinners.