The tendency to increase the sympathetic tonus in rest in all age groups especially in 4 children under school age and girls in pubertal period is revealed during the investigation of vegetative egulation by the mathematical analysis of the heart rhythm variability in children with congenital heart diseases of pale type.

State of initial vegetative tonus in 68 children of age from 7 to 13 with congenital heart diseases (of acyanotic type) was studied by mathematical analysis method of cardiac rhythm variability at pre-operation and post-operation periods. It was established, that in patients with congenital heart diseases dynamics peculiarities of vegetative nervous systems state depend on operations conditions and character of initial vegetative tonus in pre-operation period. It was determined, that most unfavourable days with great variation of vegetative characteristics are the 1st, 2 nd and also the 5 th and the 6 th days. The above said should determine therapy tactics with taking into account vegetative regulation.