State of the Upper Gastrointestinal Tract in Children with Congenital Heart Defects and Malformations of Heart Development

The dissertation is devoted to a comprehensive study of the state of the upper gastrointestinal tract in children with congenital heart defects and malformations of heart development, taking into account the ecological state of the surrounding environment and hemodynamic disturbances. The research encompasses the epidemiological characterization of the prevalence of congenital heart defects and minor heart malformations in various regions of the Krasnodar Region, analysis of the dependence of their formation on the degree of environmental contamination, as well as description of the morphofunctional features and clinical picture of gastrointestinal tract diseases in this category of patients. The relevance of the work is determined by the high prevalence of congenital heart defects and minor malformations of development in the pediatric population, as well as the necessity of accounting for concomitant abdominal pathology in the formation of an optimal therapeutic strategy.

Congenital developmental defects (CDD) are one of the major problems of modern pediatrics [Shabalov N.P., 2000; Sharykin A.S., 2000]. Among the CDD, congenital heart defects (CHD) account for 13.8% to 54.3% [1, 2, 3, 15, 69, 110, 113, 127, 139]. No less relevant is the problem of minor malformations of heart development (MMHD), which, in the opinion of most authors, do not lead to gross disturbances of the cardiovascular system (CVS) function. In the pediatric population, the frequency of MMHD amounts to 2.2–10% [2, 6, 42, 89, 94, 114, 117, 119]. At present, more than 40 variants of MMHD have been described, among which the most frequently encountered are: ectopic trabeculae, prolapse of the mitral and tricuspid valves, elongated Eustachian valve (valve flap), aneurysm of the interatrial and interventricular septum, dilation of the aortic root and sinuses of Valsalva, and others.

There are contradictory data regarding the risk factors leading to the formation of defects and developmental anomalies of the heart. In some studies, the priority is given to the effects of chemical substances and industrial hazards on the maternal organism during the period of conception and gestation of the child [8, 15, 42, 63, 105, 106, 109, 116, 117, 118, 123, 140, 141, 142, 177]. Other authors attach particular importance to acute respiratory viral infections (ARVI) [6, 8, 15, 78, 131, 132, 135, 136].

In recent years, particular significance in the formation of various diseases has been attributed to the state of the environment. The health of children is one of the most sensitive criteria reflecting ecological well-being. Particular danger for children is posed by anthropogenic pollutants of the environment. The child organism, by virtue of morphofunctional immaturity, possesses heightened sensitivity to radiation, chemical, and biological contamination of the environment [1, 2, 6, 9].

In Russia, 15% of the territory represents zones of ecological disaster, and 30% of the population resides in ecologically unfavorable regions and cities [Veltishchev Yu.E., 1994]. Approximately 20,000 children with congenital heart defects and developmental anomalies are born in Russia annually; half of them perish during the first year of life. The majority of children with CHD require surgical intervention, while the remainder are subject to long-term observation and rehabilitation in specialized medical institutions, since congenital anomalies of the heart constitute an unfavorable background for the development of intercurrent diseases.

In turn, chronic hypoxemia and impaired circulation lead to compensatory restructuring of all organ systems. All of this not only worsens the child's condition, contributes to asthenization, but also leads to the formation of concomitant diseases of other organs and systems, in particular, of the gastrointestinal tract, which aggravate the course of the primary disease.

It is known that in patients with prolonged heart failure, inflammatory diseases and functional disturbances of the gastrointestinal tract develop: gastroesophageal reflux; gastroesophageal reflux disease; peptic ulcer disease of the stomach and duodenum, cholelithiasis disease, and others.

In accordance with modern concepts, the basis of so-called minor malformations of heart development (prolapse of the mitral valve, aneurysm of the interatrial and interventricular septum, dilation of the aortic root and sinuses of Valsalva, and others) lies in genetically determined collagen insufficiency, leading to altered mechanical properties of the mitral leaflets. High collagenization of the digestive organs allows the expectation of diverse manifestations of connective tissue dysplasias of various sections of the gastrointestinal tract in patients with MMHD.

The interaction between the gastrointestinal tract and the CVS presents undoubted interest. Proximity of location to the heart, commonality of innervation are capable, by means of viscero-visceral reflexes, on the one hand, to provoke arrhythmias and worsen circulatory insufficiency; on the other hand, oxygen deficiency, low arterial blood pressure, and decreased cardiac output cause degeneration of hepatocytes, dilation of sinusoids, and slowed bile secretion.

In this connection, studying the state of the upper gastrointestinal tract in children with congenital heart defects and malformations of heart development from the standpoint of the ecological state of the surrounding environment makes it possible to identify certain clinical-pathogenetic patterns in the formation of these diseases.

The aim of the study: To investigate the morphofunctional state of the upper gastrointestinal tract in children with congenital heart defects and malformations of heart development depending on the ecological state of the surrounding environment and hemodynamic disturbances, in order to improve therapeutic and preventive measures and enhance quality of life.

The tasks of the study:

1. To determine the frequency of congenital heart defects and malformations of heart development in various regions of the Krasnodar Region.

2. To identify the dependence of the formation of congenital heart defects and minor malformations of heart development on the degree and nature of environmental contamination.

3. To study the structure of gastrointestinal tract diseases in children with congenital heart defects and malformations of heart development.

4. To describe the morphofunctional state of the upper gastrointestinal tract in children with congenital heart defects and malformations of heart development.

5. To demonstrate the features of the formation of gastrointestinal tract diseases in children with CHD and MMHD depending on various environmental contaminants and hemodynamic disturbances.

6. To determine therapeutic and preventive measures for children with CHD and MMHD in combination with diseases of the upper gastrointestinal tract.

Scientific novelty

For the first time in pediatric practice, comprehensive epidemiological investigations were conducted to study the prevalence of CHD and MMHD in the Krasnodar Region. Patterns of distribution of the frequency of CHD and MMHD across territories with different levels of environmental contamination have been demonstrated. The structure of gastrointestinal tract diseases in children with CHD and MMHD has been studied. The clinical picture and certain mechanisms of the formation of gastrointestinal tract diseases in children with congenital anomalies and defects of heart development depending on the degree of environmental contamination have been described. A complex of therapeutic and preventive measures for children with CHD and MMHD in combination with diseases of the upper gastrointestinal tract has been developed.

Practical significance

1. The conducted research contains new data on the clinical-pathogenetic features of the formation of heart defects and developmental anomalies in children.

2. New methodological approaches have been developed in the study of the processes of formation of gastrointestinal tract diseases in childhood.

3. It has been established that environmental factors are not the main causative-significant factors in the formation of congenital heart defects and minor heart malformations in children.

4. A system of diagnostic coefficients for predicting the formation of upper gastrointestinal tract diseases may serve as an effective method for preventing the development of inflammatory diseases of the upper gastrointestinal tract in children with CHD and MMHD.

5. The factual data obtained in the work on the features of the course of CHD and MMHD against the background of diseases of the upper gastrointestinal tract will allow practitioners to improve their therapeutic tactics.

Dissertation defense and implementation into practice

The results of the work have been implemented in the practice of pediatric hospitals and clinics of the city of Krasnodar and the city of Moscow. The results of the research are used in the educational process in the training of listeners and physicians at the Department of Pediatrics with Childhood Infections of the Faculty of Advanced Medical Education of the Russian State Medical University, at the Department of Pediatrics No. 1 of the Kuban State Medical Academy. Based on the dissertation materials, 9 scientific works have been published. The main provisions of the dissertation were discussed at the scientific conference "Actual Problems of Abdominal Pathology in Children" (Moscow, 2004, 2005), the X Congress of Gastroenterologists of Russia (2005), the scientific-practical conference "Sociology of Medicine – Healthcare Reform" in Volgograd (2004), and the annual Slavic-Baltic Forum "Gastroenterology – 2004, 2005".

Volume and structure of the dissertation

The dissertation is presented on 151 pages of typed text and consists of an introduction, 6 chapters, a conclusion, conclusions, and practical recommendations. It is illustrated with 31 tables and 18 figures. The bibliography includes 187 sources; of them, 44 are foreign.