[Radiocardiogram interpretation by estimating the average transit time of a tracer]

A new method for the interpretation of the radiocardiographic (RCG) data is proposed. As distinct from the widely used method developed by Donato et al. based on the exponential extrapolation of the terminal zones of the RCG peaks and the calculation of the mean time of the indicator general circulation in the body, this one is based on the approximation of both RCG peaks by gamma-image function, measurement of the indicator maximum level in the field of interest of the vena cava superior and calculation of the time indices that characterize the mean-transit time of radioactivity through the right cardiac regions and through the heart and lungs in general. On examination of practically healthy persons and 62 patients with ischemic heart disease 10 different RCG time indices were identified. The correlation matrix of the interrelationships of these indices and the matrix of the coefficients of respective regression equations were calculated. It has been established that the mean time of general circulation results in the distorted evaluation of myocardial pump function whereas time indices determined by the above method give a more adequate evaluation of the central hemodynamics.