Pulse wave transit time
The Pulse Wave Velocity (Engl. Pause time transit PTT) is a of cardiovascular reading. It describes the time that a pulse wave needs to cover a certain distance in the vascular system. By measuring the pulse wave transit time, conclusions can be drawn about important vital parameters such as blood pressure and the elasticity of the vessels.
It is determined by the pulse wave velocity (PWV) and the distance (d) over which the measurement is made.
The pulse wave velocity must not be confused with the blood flow velocity, which is significantly lower.
The most common embodiment is the measurement of the pulse wave transit time from the heart to an index finger. The start of the pulse wave, i.e. the time of the heart contraction, is determined by means of an electrocardiogram (EKG). The ECG maximum, the so-called R-wave, is often used for this purpose. The signal is detected photoplethysmographically on the finger using a pulse oximeter .
Studies have shown that the pulse wave transit time can be used to determine blood pressure at least over short periods of time. However, a reference measurement is first necessary for this.