What complication is associated with untreated atrial fibrillation?

Untreated atrial fibrillation is particularly associated with thromboembolic events, primarily due to the potential formation of blood clots within the atria. In atrial fibrillation, the irregular and often rapid heart rate can lead to stagnant blood flow in the atria, particularly in the left atrial appendage. This stagnation increases the risk of clot formation.

If these clots dislodge, they can travel to other parts of the body, such as the brain, leading to an ischemic stroke, or to the lungs, resulting in a pulmonary embolism. The risk of thromboembolic events is a major concern in patients with atrial fibrillation, which is why anticoagulation therapy is often indicated as a preventive measure in those with persistent or long-standing atrial fibrillation.

While acute heart failure, hypertension, and coronary artery spasm may be associated with conditions like atrial fibrillation or can result from it, they are not direct complications arising specifically from untreated atrial fibrillation in the way that thromboembolic events are. The connection with thromboembolic events is direct and well-documented, making it a crucial aspect of managing patients who present with this dysrhythmia.