Proximal Pulmonary Artery Blood Flow Characteristics in Healthy Children

The data on the maximum values ​​of velocity on the pulmonary valve (PV) presented in the literature are often not true. The recorded rates, as a rule, exceed the recommended values ​​even in the absence of pathology of the cardiovascular system, and in the presence of defects of the septum (ASD, VSD) or restless behavior of the child are even greater.

In order to clarify the situation, we made an attempt to revise the maximum normal speed indicators (Vmax) for PV in childhood.

A retrospective analysis of the protocols of 2030 echocardiographic studies was performed, which was performed for children aged 2 weeks to 16 years. Children with ASD, VSD, PDA and open oval windows were not included in the study. The results of the Vmax estimation (data are given in the M+2δ, m/s) on the PW-mode, taking into account the body weight of the children surveyed, were as follows:

3,3-9,9 kg - 1,06+0,27 m/s; 10.0-14.9 kg - 1.07+0.25 m/s; 15.0-19.9 kg - 1.02+0.31 m/s; 20.0-24.9 kg - 1.0+0.29 m/s; 25,0-29,0 kg - 1,0+0,26 m/s; 30.0-39.9 kg - 1.0+0.25 m/s; 40.0-60.0 kg - 1.0+0.3 m/s.

The correlation analysis made it possible to reveal only a weak negative connection of Vmax to a PV with age (r= -0.15, p<0.95), and a moderate positive correlation Vmax on a PV with Vmax on aortal valve (r= 0.43; p<0,05). In the latter case, the explanation may serve as a hyperkinetic type of hemodynamics, more often observed in childhood. In general, for the group, the average values ​​of Vmax for PV were 1.03+0.25 m/s.

Thus, the maximum normative speed indicators for PV in childhood should be revised, and set at a minimum within 0.78-1.38 m/s (for M+2δ), and this is only for the PV. For the trunk of LA speeds can be somewhat larger.