Abstract
Age-related features of the morphological and functional development of the myocardium were studied by echo- (EchoCG) and electrocardiography (ECG) in 200 children five to nine years of age. The most intensive anatomical development of myocardium was observed at the age of five to seven years, and a significant increase in cardiac output was observed at the age of eight to nine years both in boys and girls. The ECG amplitude and time parameters significantly changed from of five to nine years of age and were most pronounced at the age of seven to eight years. Different changes in cardiac rhythm and excitation conduction as well as repolarization and metabolic disturbances in the myocardium were often observed at this age. Static physical exercise caused marked changes in bioelectric activity of the myocardium. Two types of central circulatory responses to static exercise were found: an increase and a decrease in cardiac output. The mechanisms of cardiac rhythm regulation, which caused an increase in the stroke volume as a response to exercise, were different in children from five to nine years old. At the age of five to six years the homeometric mechanism was a crucial factor in the increase in stroke volume as a response to exercise, and at the age of seven to nine years both homeo- and heterometric mechanisms of cardiac rhythm regulation were very important.
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REFERENCES
Doshchitsin, V.L., Prakticheskaya elektrokardiografiya (Practical Electrocardiography), Moscow: Meditsina, 1987.
Zaretskii, V.V., Bobkov, V.V., and Ol'binskaya, L.I., Klinicheskaya ekhokardiografiya (Clinical Echocardiography), Moscow, 1979.
The Study of Left Ventricle Function according to the Readings of Unidimentional EchoCG (Methods and Norms), Metodicheskie rekomendatsii (Methodical Guidelines), Vil'nyus, 1986.
The Main Echometric Indices of the Heart in Healthy Children of 3 to 15 Years, Metodicheskie rekomendatsii (Methodical Guidelines), Moscow, 1989.
Kuberger, M.B., Rukovodstvo po klinicheskoi elektrokardiografii detskogo vozrasta (Handbook on Clinical Electrocardiography in Children), Moscow: Meditsina, 1983.
Khachatryan, T.S., Results of the Estimation of Cardiovascular System in Children of Pre-School Age, Pediatrics, 1991, no. 3, p. 111.
Rubleva, L.V., Development of the Main Myocardial Functions in Children 7-15 Years Old Living under Different Ecological Conditions, Cand. Sci. (Biol.) Dissertation, Moscow, 1999.
Chernyshov, V.N., Tarasova, E.A., and Tryasak, O.A., The Variants of Cardiac Rhythm and Conduction Disorders in Healthy Schoolchildren, Novoe v diagnostike, klinike, lechenii i profilaktike zabolevanii detskogo vozrasta: sb. nauchn. tr. (New Aspects in Diagnostics, Clinics, Therapy, and Prevention of Childhood Diseases: Collection of Sci. Papers), Rostov-on-Don, 1988, p. 85.
Kmit', G.V., Myocardial Function in Children 6-11 Years Old during Their Development and Adaptation to Educational Load, Cand. Sci. (Biol.) Dissertation, Moscow, 1992.
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Kmit', G.V., Rubleva, L.V. Age-Related Features of Morphological and Functional Development of Myocardium in Children of Five to Nine Years. Human Physiology 27, 556–560 (2001). https://doi.org/10.1023/A:1011956226233
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DOI: https://doi.org/10.1023/A:1011956226233