Systolic Pressure Slope: System for Automated Display and Calculation

Abstract

The rate of rise of arterial blood pressure—the systolic pressure slope— has been measured noninvasively at the ankle and has been shown to be reduced by minor degrees of peripheral arterial stenosis. This report describes an electronic system used to display the systolic part of the arterial pressure wave. The system uses noninvasive data from an ECG, a blood pressure cuff, and a Doppler ultrasound detector. From these data the systolic pressure slope is measured automatically. One hundred and sixty-eight recordings from the limbs of 10 normal subjects were ana lyzed in detail and confirmed the reproducibility of the system. The points used to calculate the systolic slope fell close to a straight line, with cor relation coefficients averaging 0.96. An average of eight repeat measure ments were made per limb, and the coefficients of variation averaged 6.5%. Mean values for the normalized systolic pressure slope agreed with pre viously published data.