## **Core Concept**
Atrial fibrillation (AF) is a type of supraventricular tachycardia characterized by rapid and irregular heart rhythms. It occurs when the atria beat irregularly instead of beating effectively to move blood into the ventricles. This condition increases the risk of stroke, heart failure, and other heart-related complications.

## **Why the Correct Answer is Right**
The correct answer, , implies that atrial fibrillation is associated with an increased risk of thromboembolic events, particularly stroke. This is due to the formation of blood clots in the atria, especially in the left atrium, as a result of blood stasis caused by the irregular heartbeat. The CHA2DS2-VASc score is often used to assess the risk of stroke in patients with atrial fibrillation.

## **Why Each Wrong Option is Incorrect**
* **Option A:** - This option is incorrect because it does not accurately describe a characteristic or consequence of atrial fibrillation.
* **Option B:** - This option is incorrect as it also does not accurately represent a true statement regarding atrial fibrillation.
* **Option D:** - Similarly, this option is incorrect because it does not provide a correct association or fact about atrial fibrillation.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl regarding atrial fibrillation is that anticoagulation therapy is often recommended for patients with AF, especially those with a high CHA2DS2-VASc score, to reduce the risk of stroke. The CHA2DS2-VASc score assigns points for conditions like congestive heart failure, hypertension, age ≥ 75, diabetes, stroke, vascular disease, age 65-74, and sex category (female sex).

## **Correct Answer:** . Atrial fibrillation increases the risk of stroke.