What percent of people over age 80 have atrial fibrillation?

• A. 5%
• B. 8%
• C. 10%
• D. 15%

Answer: (B)

The main idea is that how common atrial fibrillation is rises with age, and by the time people are over 80, it affects a notable portion of the population. By octogenarian years, about eight percent have atrial fibrillation. This happens because aging brings structural changes in the atria and more frequent presence of other heart risk factors like hypertension and heart failure, which promote irregular electrical activity. Clinically, this matters because AF substantially increases stroke risk, so recognizing its prevalence in the elderly helps guide screening and management, including decisions about anticoagulation based on overall risk. While some populations show numbers near ten percent, eight percent is the typical estimate used in many resources for this age group.