The international standardization of echocardiographic (echocardiography) studies on patients with a body surface area (BSA) of less than 1.5 m2, as well as in pediatric practice, requires the use of standard values ​​for the Z-score system. What is Z-Score? This is a system of quadratic deviations from the size of an organ for a healthy population, for which BSA is used, and hence the function of the heart and its size. On the basis of statistical studies, the median values ​​of sizes in a healthy population of children were revealed, in the case of exceeding 2 standard quadratic deviations, pathology.

Why not just use age norms? A baby is a fast growing organism. Children of the same age can be very different from weight and weight, and hence from the volume of the load on the heart muscle. Remember multiple nomograms for every tenth or hundredth of the surface area of ​​the body? For this and need this application. After entering data on height and weight, the program for calculating the range or walls is the results of calculating the S-indicator.

An additional function is the calculation of myocardial mass (OTS or RWT).

The program uses statistical values:

Regression equations for calculating the z-scores of heart structures in a large cohort of healthy babies, children, and adolescents: an echocardiographic study. Pettersen, MD, Du, V., Skeens, ME, Houmes, R.A. J Am Soc Echocardiogr. 2008 Aug; 21 (8): 922-34.

The function of the right ventricle in infants, children, and adolescents: reference values ​​of the tricuspid annular plane systolic excursion (TAPSE) in 640 healthy patients and calculating z-score values. Kestenberger M., Rawekes V., Everett A. D., Stuger L. P., Heinzl B., Hamilscheg A., Zwirn G., Boysen A., Fandl A., Nagel B. J Am Soc Echocardiogr. 2009 Jun; 22 (6): 715-9. Epub 2009 May 7th.

Echocardiographic nomograms for diameters of chambers and areas in Caucasian children. Cantinotti M, Scalese M, Murzie B, Assanta N, Spadoni I, De Lucia V, Crochetti M, Cresti A, Gallotta M, Marotta M, Tyak K, Molinaro S., Jerwasi JJ Sos Echocardiogr. 2014 Dec; 27 (12): 1279-1292.e2.