Functional status of the cardiovascular system in young children who had correction for congenital heart defect by the age of 1 year

Abstract

Background. The topic relevance is determined by the increasing number of children with congenital heart defect (CHD) who require surgical correction at an early age. For further follow-up it is necessary to determine a functional status of the cardiovascular system (CVS), its adaptation to new conditions of hemodynamics, that is especially important in childhood during the period of morphological and functional changes in the growing organism. Aim. To assess the functional status of the CVS in children with CHD using a test with dosed exercise load (EL) to determine the need for an individual approach to physical rehabilitation.Materials and methods. The study included 80 children, who have been surgically treated for CHD by the age of 1 year. The study population included 32 (40.0%) boys and 48 (60.0%) girls; an average age of patients was 33.5 ± 4.28 months. The control group included 50 conditionally healthy children, with an average age of 35.0 ± 4.1 months; of which 23 (46%) were boys and 27 (54%) were girls. To assess the functional status of the CVS, a test with dosed EL was performed (10 squats in 20 s). Blood pressure and heart rate were measured at rest and after exercise, the double product and the quality of response index were calculated. Results. In children with CHD 2 years after surgery, resting blood pressure was lower compared with healthy children, no significant differences in heart rate between groups were found. The double product in children of the main group was close to above average value. Analysis of hemodynamic changes due to EL showed a more pronounced increase in heart rate and less pronounced increase in pulse pressure and stroke volume in children with CHD after correction, which indicates the adaptation of CVS to EL due to an increase in the rate rather than the strength of heart contractions. The quality of response index in the group of children with CHD corresponded to an irrational reaction to EL. Analysis of CVS responses to the load showed that the most prevalent type was asymptaticotonic one (when there is an increase in heart rate and almost no changes in blood pressure). In the hypertensive type (revealed in a small number of children), there is a significant increase in both heart rate and systolic and diastolic blood pressure. The time of hemodynamics backing up to the baseline parameters did not exceed 5 minutes in both groups, no child complained during the test. Conclusions. In young children who had surgical correction for septal CHD in infancy, blood pressure is characterized by low parameters, that is associated with a possible alteration in the regulation of vascular tone. The predominant type of the CVS response to EL in young children with septal CHD which was corrected in infancy is the asympathicotonic one with a normal period of restoration of hemodynamics to the baseline parameters. The test with EL allows us to individualize the program of physical rehabilitation of young children who had surgery for septal CHD in infancy, taking into account the status of CVS and the initial fitness