Why are South Asians seemingly protected against the development of atrial fibrillation? A review of current evidence.

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia and is strongly associated with conditions such as valvular heart disease, coronary artery disease and particularly hypertension and diabetes mellitus. The South Asian ethnic group have high rates of these conditions and so would be expected to be at significant risk of AF. However, observational studies have consistently shown that South Asians have a lower prevalence of AF compared with Caucasians. This article summarizes current evidence surrounding the development of AF and its relationship to ethnicity, offers potential reasons for this disparity and identifies future areas of research.