Changing from non-pulsatile to pulsatile sinus pressure imposed a rhythm synchronous with the pump upon sympathetic activity, with a baroreceptor-sympathetic reflex delay of approximately 200 m/sec.
The study demonstrates a beat-to-beat control of cardiac activity via a baroreceptor-sympathetic reflex delay of approximately 200 m/sec in a feline model.
Simultaneous recordings of sympathetic activity in the right inferior cardiac nerve, and of baroreceptor activity in the common carotid baroreceptor nerve were made in cats with an isolated common carotid artery and sinus area. The effect of the change from non‐pulsatile to pulsatile sinus pressure was to impose a rhythm synchronous with the pump upon sympathetic activity. The changes in amplitude of sympathetic activity were investigated. The inhibition of sympathetic activity by carotid traction was used to identify sympathetic fibres. The baroreceptor‐sympathetic reflex delay was of the order of 200 m/sec. thus providing a beat to beat control of cardiac activity.
Green et al. (1968) studied this question. Change from non-pulsatile to pulsatile sinus pressure vs. Non-pulsatile sinus pressure was evaluated on Sympathetic activity rhythm and amplitude. Changing from non-pulsatile to pulsatile sinus pressure imposed a rhythm synchronous with the pump upon sympathetic activity, with a baroreceptor-sympathetic reflex delay of approximately 200 m/sec.