What is the primary cause of an embolic stroke?

An embolic stroke occurs when a blood clot or other debris forms away from the brain, often in the heart, and travels through the bloodstream to lodge in narrower brain arteries. Atrial fibrillation is a significant risk factor for embolic strokes because it can lead to the formation of blood clots in the left atrium of the heart. These clots can break loose and travel to the brain, resulting in an obstruction of blood flow which causes the stroke.

In patients with atrial fibrillation, the irregular heartbeat can cause blood to pool in the atria, increasing the risk of clot formation. Once these clots dislodge, they can travel to the cerebral arteries, leading to an embolic stroke. This mechanism highlights the connection between cardiac issues and cerebrovascular events, underscoring why atrial fibrillation is the primary cause of embolic strokes. Understanding this relationship is vital in both prevention and treatment strategies for patients at risk of strokes.