Source: Northwestern Memorial Hospital
25 percent of all stroke patients experience a cryptogenic ischemic stroke, meaning physicians are unable to determine a cause. For these patients, physicians believe atrial fibrillation, the most common type of arrhythmia (abnormal heart beat), may occur without the patient’s knowledge, causing the stroke. During atrial fibrillation, the heart’s upper chambers, or atria, quiver rather than beat; this allows blood to stay in the chamber and potentially cause a clot. If the clot travels from the heart and reaches the brain, a stroke is imminent.