Thromboembolic risk in atrial flutter compared with atrial fibrillation is...

• A. The risk is negligible
• B. The risk is higher than in atrial fibrillation
• C. The risk is lower than in atrial fibrillation
• D. The risk is comparable to atrial fibrillation

Answer: (D)

The main idea is that stroke risk in atrial flutter is similar to that in atrial fibrillation, not negligible or consistently higher or lower. Both conditions promote thrombus formation in the left atrium because of reduced or ineffective atrial contraction, leading to blood stasis. In flutter, the rapid but organized atrial activity can still impair coordinated contraction, and many patients with flutter have coexisting AF or may develop it over time, making their overall embolic risk comparable to AF.

Because the risk comes from these shared mechanisms and patient risk factors, decisions about anticoagulation are based on established stroke risk factors (like age, hypertension, diabetes, prior stroke, heart failure, vascular disease) rather than rhythm type alone. So, the thromboembolic risk in atrial flutter mirrors that of atrial fibrillation.