Determination of transcoronary circulatory transport function.

A method is described to determine the transcoronary circulatory transport function (h(t)) from input (Ci'(t)) and output (Co'(t)) dye-dilution curves obtained at the inlet and outlet of the coronary circulation. Assuming the mathematical linearity and stationarity of the coronary circulation, it is demonstrated that h(t) can be computed in terms of lagged normal density curve as a model from the sole measurement of the first to third moments of Ci'(t) and Co'(t) when recorded by a pair of our dye sampling systems that have shown to have identical response to step function. The method is useful because of its simplicity in practice. The physiological meaning of the determination of h(t) is discussed. It could be helpful to the estimation of the change in coronary path-length distribution under some conditions, although the method is still of limited value at present, because the averaged path-length through the coronary circulation cannot be evaluated correctly.