In this review we highlight current reports of IL-6 involvement in the pathogenesis of cardiac dysfunctions associated with increased vulnerability to fatal ventricular arrhythmias (long QT syndrome or LQTS) (Schwartz et al., 2009; Beitland et al., 2014) or increased morbidity (atrial fibrillation or AF) and mortality (Table 1). Here, IL6 is linked to familial long QT syndrome.