Pressure half-time in aortic regurgitation: evaluation with Doppler in a cardiovascular hydromechanical simulator and in a computer model

J Am Soc Echocardiogr. Jan-Feb 1990;3(1):46-53. doi: 10.1016/s0894-7317(14)80298-8.

Abstract

Doppler echocardiographic determination of pressure half-time has been proposed as a method of assessing the severity of aortic regurgitation. To evaluate this method, we assessed the relation between pressure half-time and simulated aortic regurgitant flow under various conditions in two models of the cardiovascular system. In a hydromechanical model we assessed the influence of total peripheral resistance and arterial compliance on the pressure half-time as measured by continuous wave Doppler echocardiography. In a computer model that used the half-time of the pressure gradient between the aorta and the left ventricle as an expression of pressure half-time, we assessed the influence of total peripheral resistance and arterial compliance and also the influence of left ventricular compliance on pressure half-time. In both models, although we found an inverse relation between regurgitant orifice area and pressure half-time, changing total peripheral resistance and arterial compliance (but not left ventricular compliance) within the physiologic range significantly altered the pressure half-times. We concluded that the influence of total peripheral resistance and arterial compliance limits the usefulness of Doppler echocardiographic determination of pressure half-time as a method of assessing the severity of aortic regurgitation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aorta / physiopathology
  • Aortic Valve Insufficiency / physiopathology*
  • Blood Pressure
  • Cardiac Output
  • Computer Simulation*
  • Echocardiography, Doppler*
  • Humans
  • Models, Structural*
  • Vascular Resistance