Journal of Applied Physiology, Vol 76, Issue 3 1378-1383, Copyright © 1994 by American Physiological Society
Regurgitant volume in aortic regurgitation from a parameter estimation procedure
S. A. Slordahl, H. F. Kuecherer, J. E. Solbakken, H. Piene, B. A. Angelsen and N. B. Schiller
Adult Echocardiography Laboratory/Cardiovascular Research Institute, University of California, San Francisco 94143-0214.
The regurgitant volume and regurgitant orifice area as well as total
peripheral resistance and arterial compliance were estimated in a
cardiovascular hydromechanical simulator and in 10 patients with aortic
regurgitation. A parameter estimation procedure based on a simple model of
the cardiovascular system, Doppler measurements of the regurgitant jet,
aortic systolic flow, and systolic and diastolic blood pressures was used.
In the cardiovascular simulator the estimated regurgitant orifice area was
compared with the size of a hole in the disk of a mechanical aortic valve.
In the patients the regurgitant fraction was compared with semiquantitative
grading from echocardiography routinely performed in our laboratory. In the
hydromechanical simulator, the estimated regurgitant orifice area of 26.5
+/- 3.5 (SD) mm2 (n = 9) was not different from the true value of 24 mm2.
In the patients there was a fair relationship between the estimated
regurgitant fraction and the semiquantitative grading. The estimated
regurgitant orifice areas varied between 1.6 and 31.2 mm2. The estimated
mean values of total peripheral resistance and arterial compliance were
1.67 +/- 0.55 mmHg.s.ml-1 and 1.30 +/- 0.42 ml/mmHg, respectively.
