Which type of arrhythmia is most associated with a risk of stroke?

Atrial fibrillation is the type of arrhythmia most associated with a risk of stroke. This condition involves an irregular and often rapid heartbeat that can lead to poor blood flow. When the heart's atria (the upper chambers) fibrillate or quiver instead of contracting effectively, blood can pool in these chambers, especially in the left atrial appendage. This stasis of blood increases the likelihood of clot formation. If a clot dislodges, it can travel to the brain, resulting in a stroke.

The risk of stroke in patients with atrial fibrillation is significant, and it is often quantified using scoring systems like the CHA2DS2-VASc score, which helps determine appropriate anticoagulation therapy to reduce stroke risk. Atrial flutter, while also an arrhythmia, does not have the same stroke risk profile as atrial fibrillation. Ventricular tachycardia and ventricular fibrillation are typically more associated with sudden cardiac arrest and may not have the same prolonged risk for stroke like atrial fibrillation does.