Which of the following is a predisposing factor for strokes?

• A. Regular exercise
• B. Atrial fibrillation
• C. Healthy weight
• D. Vitamin deficiency

Answer: (B)

Atrial fibrillation stands out as a predisposing factor for stroke because it disrupts normal atrial contractions, causing blood to pool and form clots in the left atrium, especially the left atrial appendage. These clots can break off and travel to cerebral arteries, blocking blood flow and causing an ischemic stroke. This is a major, modifiable risk factor that can be reduced with anticoagulation or other therapies.

Regular exercise and a healthy weight actually lower stroke risk by improving blood pressure, lipid, and glucose profiles and reducing vascular inflammation, so they are protective rather than predisposing. Vitamin deficiency is not a typical direct predisposing factor for stroke in most exams, though severe deficiencies can impact overall health.