Does the baroreceptor-heart rate reflex indicate the capacity of arterial baroreceptors to control blood pressure?
The baroreceptor-heart rate reflex is a poor indicator of the capacity of arterial baroreceptors to control blood pressure, particularly during exercise or in hypertension.
We have examined the question asked in the title by studying: the carotid baroreceptor reflex in man with a variable-pressure neck chamber; the carotid baroreceptor reflex in conscious rabbits with a variable-pressure capsule around the carotid bifurcation; and the barorecptor-heart rate reflex. 2. At rest, the association between the sensitivities of the carotid baroreceptor-blood pressure and -heart rate reflexes, and of these with the baroreceptor-heart rate reflex, is weak. Exercise causes dissociation between control of blood pressure and heart rate. In hypertension, depression of the baroreceptor-heart rate reflex does not reflect the altered characterisitics of the carotid sinus-blood pressure reflex.
Ludbrook et al. (Wed,) studied this question.