| Abstract: | Summary On narcotised dogs, the carotid sinus nerve was stimulated by means on electrical R-wave-triggered pulse trains when depressor nerves were either intact or cut.The stimulation was begun in the range from 0–210 msec after the R-wave. The effectiveness of pulse trains was determined by the level of reduction in mean arterial pressure.In the time range studied, the level of reduction in pressure versus time of stimulation shows two maxima of reduction at 30 and 90 msec and a plateau from 110–150 msec. Stimuli applied later than 150 msec after the R-wave, display a contnuous reduction in effectiveness.The occurrence of the maxima is considered to be due to a coincidence of the pressor afferences from heart, aortic arch and carotid sinus, arriving at the circulatory centres spaced in time with the electrical stimuli.The times at which the maxima of reduction are found to occur could be significant in programming baropacers. |
