Changes in heartbeat-evoked potentials reflect changes in blood pressure.

The heartbeat-evoked potential (HEP) is a growingly used electrophysiological method to study cardiac interoception; however, cardiovascular influences on these responses are not fully understood. In the present study, we studied the effect of changes in blood pressure through positional modifications and slow-paced breathing on HEP. Eighteen volunteers (22 ± 1.79 yr old) underwent 5-min tasks in upright and supine positions, with spontaneous and slow-paced breathing at 6 cycles/min. We continuously recorded blood pressure, electrocardiography, and high-density (128 electrodes) electroencephalography (EEG). We observed an increase in early (around 200 ms) and late (around 400 ms) HEP components in the supine position (P < 0.001) and more pronounced with slow-paced breathing (P < 0.001). HEP exhibited a frontocentral topography, and source modeling indicated mainly insular and cingulate cortex of the early component, which extended to frontal regions during the late component (P < 0.05). Diastolic (DBP) and pulse (PBP) blood pressure increased in an upright position (P < 0.05), whereas baroreflex sensitivity (BRS) increased in the supine position (P < 0.001). Changes in early and late HEP were mainly correlated to changes in PBP (r = 0.55; r = 0.49, respectively, P < 0.001), DBP (r = -0.35; r = -0.35, P < 0.010), and BRS (r = 0.61; r = 0.47, P < 0.001). The present study demonstrated modulations of HEP according to cardiovascular activities, suggesting a heightened integration of baroreflex afferents by positional modulations and to a lesser extent by respiratory modulations. These changes should be considered in assessments of interoception in clinical populations.NEW & NOTEWORTHY Heartbeat-evoked potentials (HEPs) allow to explore the interaction between cardiovascular and central nervous systems, showing that interoceptive processing may influence cognitive, emotional, and sensorimotor functions. However, the extent to which cardiovascular dynamics modulate HEPs remains unclear. Here, we demonstrate that cardiovascular changes alter both early and late cortical responses, indicating that HEPs are strongly influenced by the cardiovascular system.