AJP - Heart and Circulatory Physiology, Vol 256, Issue 3 906-H915, Copyright © 1989 by American Physiological Society
Coronary sinus pressure and arterial flow during intermittent coronary sinus occlusion
F. Neumann, W. Mohl and W. Schreiner
Second Surgical University Clinic, Vienna, Austria.
The relationship between coronary artery flow and coronary venous pressure
during intermittent coronary sinus occlusion was studied in dogs at normal
perfusion, left anterior descending artery occlusion, and reperfusion.
Coronary sinus occlusion and release phases were varied systematically. The
periodicity of the data and the assumption of a linear relationship between
pressure and flow suggested Fourier analysis as a methodological approach.
To show the systematic slow oscillations of coronary venous pressure and
arterial flow induced by intermittent occlusion of the coronary sinus, the
data were smoothed by superimposing consecutive cycles of identical
occlusion-release timing and filtering the higher frequencies. A small
number of Fourier components, corresponding to the time scale of the
respective occlusion-release cycle, was sufficient to study the long
wavelength behavior. The effect of arbitrarily varying the
occlusion-to-release ratio at a given total cycle length was investigated
in hypothetical pressure and flow curves based on interpolation of
experimental Fourier coefficients. By means of a transfer function relating
pressure and flow in the frequency domain, it was possible to predict the
arterial flow curve using coronary venous pressure measurements only.
Because at zero frequency the pressure-flow relationship cannot be assumed
to be linear, the mean value of flow could not be obtained in this way.
However, the deviation of flow from the mean, i.e., the shape of the flow
curve, was reproduced satisfactorily.
