We evaluated the cardiac reflex response towards activation (CBA) and inactivation (CBI) of left and right carotid baroreceptors in two groups of healthy subjects: twenty men aged between 20-40 (I) and twenty men aged between 41-60 (II). CBA was evoked by the application of a negative pressure to the left and right carotid sinus regions, separately. CBI was produced by the application of left and right positive pressures. Suction or pressure were delivered by means of two small neck capsules. The heart rate (expressed by R-R interval [RRI]) was continuously measured. Right and left baroreflex heart rate response (GHR) advantages were determined from maximal RRI response pressure neck capsule changes. Differences between right and left carotid sinus responses were only noted in the I group of subjects. The maximal response of the RRI was greater during right CBA/CBI than during the left. In older (II) subjects the right and left carotid cardiac response increase did not differ. In conclusion we may note that in humans the carotid sinus cardiac reflex functional asymmetrys disappears with age.

Keywords: cardiac physiology, functional asymmetry, age, cardiac baroreflex