The continuous measurement of arterial pulse wave velocity

It has long been known that arterial pulse wave velocity (PWV) depends on arterial extensibility. Since extensibility is a function of arterial pressure, as well as of various pathological states, the measurement of PWV provides a promising approach to the indirect monitoring of the cardiovascular system. The present paper describes a Pulse Wave Velocity Computer designed to measure and record PWV in humans. Utilizing the EKG complex and a downstream pulse signal to define pulse-transit-time over a known arterial length, the computer calculates an individual velocity value for each emitted pulse, and generates a continuous, stepwise-analog record of the PWV. Some initial experimental work with human subjects is presented. Observations are reported for the PWV during rest, during deep breathing, and during execution of Valsalva maneuvers. In all cases the continuous PWV record appears to follow closely variations in arterial pressure, apparently adhering, in the Valsalva results, more to systolic than diastolic changes. Observed subject differences attest to the PWV's diagnostic value, and it is suggested that the continuous PWV may be a significant and useful circulatory indicant.