抄録
The authors at first made formula from which assumed normal cardiac size could be calculated in reference to body-weight and length. Actual cardiac size/assumed normal cardiac size was called dilatation-gradient : actual cardiac size was measured by planimeter in its shadow in the direct postero-anterior projection of X-ray. Relatiohship between circulation time and dilatation-gradient was investigated in cases of congestive heart failure and non-congestive cardiac disease, and linear relationship was demonstrated between them. This does not mean that prolongation of real circulation time (decrease of blood velocity) is due to dilatation of heart. Because circulation-time, clinically used, shows not only the blood velocity but also the degree how much the drug injected is diluted by blood.
