The relationship between an increase in total peripheral resistance and reflected wave: wave intensity analysis using a circulation model

Abstract

[Purpose] Total peripheral resistance (TPR) and reflected wave from the lower body affect blood pressure. However, the relationship between them is obscure. Wave intensity (WI) is a hemodynamic index, which is defined as WI=(dP/dt)(dU/dt) (P:pressure, U:velocity), and indicates ventriculo-arterial coupling. The negative values of WI indicate that reflected wave is predominant. We investigated the relationship between the negative value (NA) and TPR using a circulation model. [Methods] A circulation system was fabricated incorporating artificial elastic vessels and a syringe pump. WI was measured by ultrasonography. TPR was manipulated by clamping a peripheral tube, and the reflection points were adjusted by moving the clamp positions. [Result] The increase in TPR increased the NA, and moving the clamp position further from the pump delayed the time of NA emersion. [Conclusion] NA is an indicator of the strength of TPR and the distance from the point where the reflection wave is produced.