A genetic variant affecting the cardiac sodium channel has been found to influence the propensity for ventricular arrhythmias in African-American patients with systolic heart failure (HF)

The study represents the first report that the S1103Y variant modulates arrhythmia risk in this patient population. African Americans disproportionately suffer from HF, ventricular arrhythmias, and sudden cardiac death (SCD) when compared to whites. The researchers hypothesized that acquired arrhythmias might be associated with the common S1103Y variant in the cardiac sodium channel gene SCN5A. S1103Y is found almost exclusively in people of African descent and has a prevalence of 13% among African Americans; it is known to be associated with life-threatening arrhythmias, SCD, and sudden infant death syndrome. The specific association between the S1103Y genotype and an increased risk of arrhythmia in HF may have particular significance as a novel risk factor for African Americans.