Modeling of critical conditions of the cardiovascular system of a child with an interventricular septal defect

The relevance of this study is driven by the need to develop a mathematical model of hemodynamics for pediatric patients with congenital heart disease, capable of predicting the dynamics of cardiovascular system parameters throughout ontogeny. The creation of such a model enables the identification of the onset of critical conditions and allows for the proactive planning of treatment measures, ultimately aiming to reduce child mortality rates. The methodology for predicting the state of the cardiovascular system is based on the application of a multi-scale time 0D model of blood circulation that accounts for the presence of a ventricular septal defect. The model uses clinically measurable parameters as input data: pressure in the left and right ventricular cavities, minute blood flow volumes in the pulmonary and systemic circulation, the size of the anatomical defect, as well as the patient's age, sex, and anthropometric indicators. To address the task, a quasi-stationary approach was developed, within which the model parameters change according to the patient's age based on exponential patterns. Calibrating the model requires only the current parameter values for a specific patient and reference values for the same parameters for an average individual of the corresponding sex at a different point in time. The implementation of the proposed method allows for the assessment of the cardiovascular system's condition in children with congenital heart disease at any stage of age-related development. This model is integrated into a clinical decision support system to optimize the timing of surgical correction. Based on the model's predictive potential, a method for calculating key hemodynamic parameters has been proposed and investigated. The following criteria are proposed as predictors for the onset of a critical state with a specified accuracy: the ratio of the minute blood flow volume in the pulmonary circulation to the minute blood flow volume in the systemic circulation, and the ratio of the pressure in the left ventricle to the pressure in the right ventricle.

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