PRL and cardiac arrhythmia: Gender differences in the prevalence of certain arrhythmias suggest a correlation between sex hormones and the risk of developing arrhythmias.1–4 Hormonal influence on ion channel function can cause alterations in the action potential in cardiac myocytes leading to changes in the heart rate-corrected QT (QTc) interval, especially in channelopathies like long QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia.5 Prolactin and oxytocin hormones can also affect the regulation of transcriptional processes.