Rhythms of the Female Heart: The Impact of Cycling Sex Hormones on Cardiac Signaling and Interoception

Every month, over two billion females around the world menstruate. In addition, an estimated 400 million females globally use hormonal contraception (""the pill""). Consequently, from puberty to menopause, the female heart and brain are continuously exposed to cyclical changes in sex hormones, e.g., associated with the menstrual cycle or hormonal contraceptive use, with direct implications for neuro-cardiac health. Both psychological symptoms and specific cardiac arrhythmias show an increased prevalence and burden during specific phases of the menstrual cycle. Given this association, it becomes evident that the menstrual cycle is a key factor in understanding the heart-brain connection and its effect on psychological and cardiac health. This project aims to reveal how two recently identified markers of the heart-brain axis relevant for psycho-cardiac health, i.e., cardiac signaling (denoting neural responses to cardiac signals) and cardiac interoception (denoting conscious awareness of signals arising from the heart), varies with sex, menstrual cycle phase, and hormonal contraceptive use. To this end, we will (1) utilize a novel psychophysiological task to assess cyclical and group changes in heartbeat detection