Simple Formulae for Calculation of Cardiac Output and Mean Transit Time from Dye Dilution Curve

Abstract

In this paper A simple method for calculation of cardiac output and mean transit time from dye-dilution curve was investigated with the use of gamma distribution function
An approximation derived from the property of the function gave the following formulae :
cardiac output=_??_
mean transit time=T_p+1.1× (T2-T₁) (sec)
Where, I : amount of dye injected, C_p : peak concentration, T_p : time of peak concentration, T₁andT₂ : forward and backward parts of half width, respectively.
The values calculated with these formulae were compared with those calculated with Hamilton's method for 51 recordings of 16 patients without arterio-venous shunting or regurgitation in the heart. The discrepancies of calculated cardiac outputs and mean transit times with the two methods were less than 2.1% and 3.2%, respectively.