Sympathetic Nerve Activity-Induced Blood Pressure Fluctuations are Stacked on Linearly: A Simulation Study

A possible mechanism to fit the empirical relationship between the power spectrum of the variability of sympathetic nerve activity (P-SNA) and blood pressure (P-BP) is described. Since the BP rise depends on the magnitude of SNA with an S-mode relationship, we assume that a single BP rise is independent of the SNA frequency, while two successive SNA-induced BP fluctuations are stacked on linearly. The damping function was used to model the BP fluctuations caused by SNA, and the box function was used to model the SNA compound action potential. We quantified the logistic relationship (P-SNA = cP(BP) . 10(kf)) between the frequency and power spectrum of these two functions. The simulation data showed the physiological rationality of the empirical relationship between the P-SNA and P-BP and supported the assumption that the BP stack-on is linear and independent of the SNA frequency.