Dynamic baroreflex properties at various carotid sinus pressures during vagal afferent activation

The function of baroreflex may be modulated in cardiovascular diseases generating the dysfunction of the autonomic nervous system. The purpose of this study was to identify the dynamic baroreflex properties from various step pressure (40-160 mm Hg) responses during vagal afferent activation in rabbits. The wavelet-based time-frequency analysis was able to reveal the various transfer functions of baroreflex from the transient responses, regardless of a short-term test and poor signal to noise ratio; the dynamic gains were significantly attenuated at the nonlinear carotid sinus pressure points during the vagal activation. The current results suggest the risk of bluntness of baroreflex ability in acute myocardial ischemia, which may cause the vagal afferent activation.