“…Lability increases as the blood pressure level rises, though less than when expressed as a percentage of the mean pressure; it also increases with increasing age (9,12). Clinical physiologists have shown that blood pressure becomes more vari-4868 -155-able as the sensitivity of the baroreflexes declines in hypertensive subjects (4,5) and, strangely, the variations in heart rate decline as the blood pressure variability increases (7,13). However, when it is realized that the baroreflex influences the blood pressure in large measure by moderating cardiac function, it can be appreciated that, as the baroreflex sensitivity declines, the heart rate will increase and its variability will decrease.…”