Effects of sex hormones on cardiac ion channels involved in ventricular repolarization

Abstract Sex differences in cardiac electrophysiology and vulnerability to inherited or acquired arrhythmias are well described in basic science, clinical, and epidemiological studies. To date, the most extensively studied male–female differences pertain to ventricular repolarization and susceptibility to ventricular arrhythmias. Relative to men, women exhibit longer rate-corrected QT interval and are at higher risk of drug-induced ventricular tachyarrhythmia Torsade de Pointes. Reasonable evidence exists to suggest that these sex differences arise in part from complex and dynamic regulations of cardiac ion channels by male and female sex hormones. This chapter summarizes sex differences in ventricular repolarization, chronic and acute regulation of cardiac ion channels by sex hormones, and the net impact of sex hormones on ventricular repolarization and arrhythmia propensity.