Computational model-based assessment of baroreflex function from response to Valsalva maneuver

Area of Science:

• Cardiovascular physiology
• Autonomic nervous system function
• Aging research

Background:

• Baroreflex sensitivity is a key indicator of autonomic control and cardiovascular risk.
• Aging is associated with decreased baroreflex sensitivity, potentially contributing to hypertension.
• Assessing baroreflex function is vital for understanding cardiovascular health and disease etiology.

Purpose of the Study:

• To develop and apply novel methods for assessing baroreflex function during the Valsalva maneuver in humans.
• To investigate the relationship between aging, baroreflex response time, and resting systolic pressure.
• To differentiate the roles of carotid sinus and aortic arch baroreceptors in the heart rate response.

Main Methods:

• Developed two complementary methods: a linear filter model and a physiologically based model.
• Applied these models to heart rate data from healthy volunteers performing the Valsalva maneuver.
• Analyzed changes in arterial pressure and R-R intervals to assess baroreflex arc dynamics.

Main Results:

• Both models indicated that baroreflex response time increases with age in healthy subjects.
• Baroreflex response time was identified as a predictor of resting systolic pressure.
• The physiologically based model revealed distinct contributions of carotid and aortic baroreceptors to the heart rate response.

Conclusions:

• The developed methods provide new insights into baroreflex function and its age-related changes.
• Increased baroreflex response time is a significant predictor of systolic pressure, even in normotensive individuals.
• The study highlights differential afferent signaling from various baroreceptors influencing cardiovascular regulation.