Low prevalence of atrial fibrillation in Amerindians: a population-based study in frequent fish consumers living in rural coastal Ecuador (The Atahualpa Project).

Background: Information on the burden of atrial fibrillation (AF) in rural areas of developing countries is limited. Here, we aimed to assess AF prevalence in community-dwelling older adults living in rural Ecuador.
Methods: Atahualpa residents aged ≥60 years (mean age 70.5 ± 8.1 years) underwent 24-h Holter monitoring. Participants belong to the Amerindian ethnic group. The mean height in the study population was 147.9 ± 8.9 cm. Oily fish was a major source of food (mean intake: 8 ± 4 servings/week).
Results: Seven of 298 participants (2.3%) had AF. Persons with AF were older than those without (p = 0.051), but there were no differences in cardiovascular risk factors across groups. None of the seven AF cases had been detected in routine 12-lead ECGs taken at enrollment.
Conclusions: Prevalence of AF in older Amerindians living in rural Ecuador is low. Both, racially-determined short stature and frequent dietary oily fish intake might explain the low prevalence of AF in this rural setting.