Evaluation of baroreceptor reflex by blood pressure monitoring in unanesthetized cats

The arterial baroreceptor control of the sinus node operating in unanesthetized conditions was evaluated in 10 cats in which blood pressure was recorded intra-arterially and scanned by a computer to identify the "spontaneous" sequences of three or more consecutive beats in which systolic blood pressure (SBP) progressively rose and pulse interval (PI) progressively lengthened (type 1 sequences) or SBP progressively fell and PI progressively shortened (type 2 sequences). The data validate a method for collecting a large number of observations on the baroreceptor-heart rate reflex in physiological conditions.