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

Area of Science:

• Neuroscience
• Cardiovascular Physiology
• Electrophysiology

Background:

• The heartbeat-evoked potential (HEP) is an electrophysiological measure for studying cardiac interoception.
• Understanding cardiovascular influences on HEPs is crucial for accurate interoception assessments.
• Previous research has not fully elucidated how blood pressure and breathing affect HEPs.

Purpose of the Study:

• To investigate the impact of blood pressure variations, induced by positional changes and slow-paced breathing, on HEP components.
• To explore the relationship between cardiovascular parameters (blood pressure, baroreflex sensitivity) and HEP modulations.
• To determine the cortical regions involved in processing these cardiovascular influences on HEPs.

Main Methods:

• Eighteen healthy volunteers participated in the study.
• Continuous recording of blood pressure, electrocardiography, and high-density electroencephalography (EEG) during distinct tasks.
• Tasks included spontaneous and slow-paced breathing (6 cycles/min) in both upright and supine positions.

Main Results:

• HEPs showed increased early (approx. 200 ms) and late (approx. 400 ms) components in the supine position, further enhanced by slow-paced breathing.
• Source modeling identified insular and cingulate cortex involvement for early HEPs, extending to frontal regions for late HEPs.
• HEP changes significantly correlated with pulse blood pressure, diastolic blood pressure, and baroreflex sensitivity.

Conclusions:

• Cardiovascular dynamics, particularly blood pressure and baroreflex sensitivity, significantly modulate HEPs.
• Positional changes and respiratory patterns influence the integration of baroreflex afferents, impacting cortical processing of cardiac signals.
• Findings highlight the importance of considering cardiovascular influences in interoception studies, especially in clinical populations.