[On the splitting of the second sound in early infancy (author's transl)].

The increase of the A2-P2 interval and the linear correlation between the increase of this interval and the decrease of the ratio right: left ventricular forces on the ratio right: left ventricular forces on the ECG is in accordance with recent explanation of the mechanism of the second sound. The asynchronism between the two components of the second sound should be due to the difference in resistance and capacity of the two circulations that takes place in the first month of life.