Pulse Transit Time as an Indicator of Arterial Blood Pressure

ABSTRACT The relationship between pulse‐arrival times and diastolic blood pressure was measured in 10 anesthetized dogs. The pulse‐arrival time was measured using the R‐wave of the electrocardiogram (ECG) as a time reference. Pulse‐transit time was also measured between the carotid and femoral pulses. Blood pressure was raised with epinephrine injected intravenously and lowered with vagal stimulation. In all cases, pulse arrival and transit times decreased with an increase in diastolic pressure for diastolic pressures ranging from 15 to 250 mmHg. The correlation between pulse‐arrival time and pressure was poorest when the ECG was used as a timing reference. The best correlation was found with true pulse‐transit time and diastolic pressure. When pulse‐transit time was used to compute pulse‐wave velocity, it was found to increase nearly linearly with blood pressure. From 90–100 mmHg, the pulse‐wave velocity increased typically by slightly less than six percent.