Congenital heart defect is an anomaly in the structure of the heart or large vessels.
Information Pathology of the cardiovascular system is very common (about 1% of all newborns). Children with such diseases are characterized by high mortality in the absence of timely treatment: up to 70% of patients die in the first year of life.
According to statistical data, if we take into account the entire set of defects, there is a greater prevalence of anomalies of the cardiovascular system in boys, but some types birth defects hearts are more common in girls.
There are three groups of congenital heart defects according to the frequency of occurrence in males or females:
- "Male" vices: coarctation of the aorta (often in combination with a patent ductus arteriosus), transposition of the main vessels, aortic stenosis, etc.;
- "Women's" vices: open arterial defect, atrial septal defect, Fallot's triad, etc.;
- Neutral vices(occurs with equal frequency in boys and girls): atrioventricular septal defect, aortopulmonary septal defect, etc.
Causes of birth defects
The formation of congenital malformations of the heart and large vessels occurs in the first 8 weeks of pregnancy under the influence of various factors:
- Chromosomal abnormalities;
- Bad habits of the mother (, drug addiction);
- Unreasonable reception medicines;
- Infectious diseases of the mother (, herpetic infection and etc.);
- Hereditary factors (presence of heart disease in parents and close relatives significantly increases the risk of cardiovascular abnormalities in a child);
- Age of parents (man over 45 years old, woman over 35 years old);
- Adverse effects chemical compounds(gasoline, acetone, etc.);
- Radiation exposure.
Classifications
At the moment, there are many classifications of congenital anomalies of the cardiovascular system.
In 2000 it was adopted International nomenclature congenital heart defects:
- Hypoplasia of the right or left heart(underdevelopment of one of the ventricles). It is rare, but is the most severe form of defects (most children do not survive to surgery);
- Obstruction defects(narrowing or complete closure of the heart valves and large vessels): aortic valve stenosis, stenosis pulmonary valve, bicuspid valve stenosis;
- Partition defects: atrial septal defect, ventricular septal defect;
- Blue vices(leading to skin cyanosis): tetralogy of Fallot, transposition of the main vessels, tricuspid valve stenosis, etc.
Also in practicing medicine the following classification is often used:
- “Pale” defects of the cardiovascular system(without cyanosis): defects of the interatrial and interventricular septa, patent ductus arteriosus, etc.;
- "Blue Vices"(with pronounced bluishness of the skin): tetralogy of Fallot, transposition of the great vessels, etc.;
- Cross-blood defects(a combination of “blue” and “pale” defects);
- Defects with impaired blood flow: stenosis of the aortic, pulmonary or mitral valves, coarctation of the aorta, etc.;
- Heart valve defects: tricuspid or mitral valve insufficiency, valve stenosis pulmonary artery and aorta, etc.;
- Defects of the coronary arteries of the heart;
- Cardiomyopathy(defects of the muscular parts of the ventricles);
- Heart rhythm disturbances, not caused by a defect in the structure of the heart and large vessels.
List of the most common congenital heart defects
| Group of vices | Name of the vice | Explanations |
| Isolated defects | Ventricular septal defect | Presence of communication between two ventricles |
| Atrial septal defect | The presence of communication between the two atria | |
| Atrioventricular septal defect | Combination of structural defects of the interventricular and interatrial septa and ventricular valves | |
| Aortic stenosis | Narrowing of the aortic valve | |
| Mitral valve stenosis | Narrowing of the opening between the left ventricle and left atrium | |
| Tricuspid valve stenosis | Narrowing of the opening between the right ventricle and right atrium | |
| Pulmonary valve stenosis | Narrowing of the pulmonary valve | |
| Hypoplasia of the right heart | Disorders of the muscular apparatus of the right ventricle | |
| Hypoplasia of the left heart | Disorders of the muscular apparatus of the left ventricle | |
| Transposition of the great vessels | Incorrect position of the main vessels leaving the heart (aorta, pulmonary artery) | |
| Dextrocardia | Right-sided location of the heart | |
| Pulmonary atresia | Fusion of the pulmonary artery, lack of communication between it and the right ventricle | |
| Duplication of the right or left ventricular outlet | The pulmonary artery and aorta emerge from the same ventricle (right or left, respectively) | |
| Persistent truncus arteriosus | Only one large vessel leaves the heart, providing blood circulation to the heart and throughout the systemic and pulmonary circulation | |
| Infects only large vessels (aorta and pulmonary artery) outside the heart | Coarctation of the aorta | Narrowing of the aorta in a specific area |
| Aortic atresia | Narrowing of the aortic valve | |
| Open arterial defect | The presence of a vessel providing communication between the pulmonary artery and the aorta. Normally exists only in the prenatal period | |
| Full or partial anomaly connections of pulmonary veins | Atrial septal defect in which the pulmonary veins are connected directly to the right atrium | |
| Combined defects | Triad of Fallot | Atrial septal defect Pulmonary stenosis Enlargement of the right ventricle |
| Tetralogy of Fallot | Pulmonary stenosis Enlarged right ventricle Ventricular septal defect Dextraposition of the aorta | |
| Sean's anomaly | Left atrioventricular valve insufficiency Enlarged left atrium |
Clinical signs
Additionally The set of clinical signs depends primarily on the type of defect and its severity. Most often, symptoms appear in the first weeks and months after the birth of a child, but they can also be diagnosed accidentally, without showing anything.
All Clinical signs congenital heart defects can be grouped into the following groups :
- Cardiac signs: rapid heartbeat or rhythm disturbances, pain in the heart area, pallor or bluishness of the skin, swelling of blood vessels in the neck, deformation chest(“heart hump”), etc.;
- Heart failure with certain manifestations(acute or chronic form, left ventricular or right ventricular);
- Chronic hypoxia(oxygen deficiency);
- Respiratory disorders(more often with heart defects with changes in the pulmonary circulation).
Diagnosis of congenital heart defects
The main diagnostic measures include:
In some cases, it is possible to carry out several stages of surgical intervention.
Drug treatment is used as an adjunct to surgery:
- Drugs that improve metabolic processes in the myocardium(asparkam, );
- Preparations to improve microcirculation(xanthine nicotinate);
- Drugs for the treatment of arrhythmia;
- Medicines to normalize blood pressure(propranolol);
- Cardiac glycosides(digoxin).
Forecast
The prognosis depends entirely on the type and severity of the birth defect. If the disease is detected early and it is possible radical treatment, then the prognosis is favorable in most cases. In case of severe heart defects, when there is no possibility of complete treatment, the prognosis is questionable.
Congenital heart defects arise as a result of disruption of the formation of the heart and the vessels extending from it. Most defects disrupt the flow of blood inside the heart or through the large (BCC) and pulmonary circulation (MPC) circles. Heart defects are the most common birth defect and are the leading cause of childhood death from birth defects.
Etiology. The cause of congenital heart disease may be genetic or environmental factors, but usually a combination of both. The most well-known causes of congenital heart defects are point gene changes, or chromosomal mutations in the form of deletion or duplication of DNA segments. Major chromosomal mutations such as trisomies 21, 13 and 18 cause about 5-8% of cases of congenital heart disease. Genetic mutations occur due to the action of three main mutagens:
Physical mutagens (mainly ionizing radiation).
Chemical mutagens (phenols of varnishes, paints; nitrates; benzpyrene from smoking; alcohol consumption; hydantoin; lithium; thalidomide; teratogenic medications - antibiotics and CTP, NSAIDs, etc.).
Biological mutagens (mainly the rubella virus in the mother’s body, leading to congenital rubella with Greg’s characteristic triad - congenital heart disease, cataracts, deafness, as well as diabetes mellitus, phenylketonuria and systemic lupus erythematosus in the mother).
Pathogenesis. There are two leading mechanisms.
1. Impaired cardiac hemodynamics → overload of the heart parts by volume (defects such as valve insufficiency) or resistance (defects such as stenosis of the orifices or vessels) → depletion of the involved compensatory mechanisms → development of hypertrophy and dilatation of the heart parts → development of heart failure (and, accordingly, disorders systemic hemodynamics).
2. Disturbance of systemic hemodynamics (plethora/anemia of MCC and BCC) → development of systemic hypoxia (mainly circulatory with white defects, hemic with blue defects, although with the development of acute left ventricular HF, for example, both ventilation and diffusion hypoxia occur) .
Classification:
CHDs are conventionally divided into 2 groups:
1. White(pale, with left-right shunting of blood, without mixing arterial and venous blood). Includes 4 groups:
With enrichment of the pulmonary circulation (patent ductus arteriosus, atrial septal defect, ventricular septal defect, AV communication, etc.).
With depletion of the pulmonary circulation (isolated pulmonary stenosis, etc.).
With depletion of the systemic circulation (isolated aortic stenosis, coarctation of the aorta, etc.)
Without a significant disturbance of systemic hemodynamics (heart dispositions - dextro-, sinistro-, mesocardia; cardiac dystopia - cervical, thoracic, abdominal).
2. Blue(with right-left discharge of blood, with mixing of arterial and venous blood). Includes 2 groups:
With enrichment of the pulmonary circulation (complete transposition of the great vessels, Eisenmenger complex, etc.).
With depletion of the pulmonary circulation (tetralogy of Fallot, Ebstein's anomaly, etc.).
Clinical manifestations of congenital heart disease can be combined into 4 syndromes:
Cardiac syndrome(complaints of pain in the heart, shortness of breath, palpitations, interruptions in cardiac function; upon examination - pallor or cyanosis, swelling and pulsation of the vessels of the neck, deformation of the chest like a cardiac hump; palpation - changes in blood pressure and characteristics of the peripheral pulse, changes in the characteristics of the apical impulse with hypertrophy/dilatation of the left ventricle, the appearance of a cardiac impulse with hypertrophy/dilatation of the right ventricle, systolic/diastolic cat purr with stenosis; percussion - expansion of the boundaries of the heart according to the expanded sections; auscultation - changes in rhythm, strength, timbre, monolithic tones, the appearance of characteristic each noise defect, etc.).
Heart failure syndrome(acute or chronic, right or left ventricular, dyspnea-cyanotic attacks, etc.).
Chronic systemic hypoxia syndrome(growth and development retardation, symptoms drumsticks and watch glasses, etc.)
Respiratory distress syndrome(mainly with congenital heart disease with enrichment of the pulmonary circulation).
Complications of congenital heart disease:
Heart failure (occurs in almost all congenital heart diseases).
Bacterial endocarditis (more often observed with cyanotic congenital heart disease).
Early prolonged pneumonia against the background of stagnation in the pulmonary circulation.
High pulmonary hypertension or Eisenmenger syndrome (typical of congenital heart disease with enrichment of the pulmonary circulation).
Syncope due to small output syndrome up to the development of cerebrovascular accident
Angina syndrome and myocardial infarction (most typical for aortic stenosis, anomalous origin of the left coronary artery).
Dyspnea-cyanotic attacks (occur in tetralogy of Fallot with infundibular stenosis of the pulmonary artery, transposition of the great arteries, etc.).
Relative anemia - with cyanotic congenital heart disease.
Pathological anatomy. With congenital heart defects, the process of myocardial hypertrophy in children in the first 3 months of life involves not only an increase in the volume of muscle fibers with hyperplasia of their ultrastructures, but also true hyperplasia of cardiomyocytes. At the same time, hyperplasia of reticulin argyrophilic fibers of the cardiac stroma develops. Subsequent dystrophic changes in the myocardium and stroma, up to the development of micronecrosis, lead to the gradual proliferation of connective tissue and the occurrence of diffuse and focal cardiosclerosis.
Compensatory restructuring of the vascular bed of a hypertrophied heart is accompanied by an increase in intramural vessels, arteriovenous anastomoses, and smallest veins (the so-called vessels of Viessen-Tebezia) of the heart. Due to sclerotic changes in the myocardium, as well as increased blood flow in its cavities, thickening of the endocardium appears due to the growth of elastic and collagen fibers in it. Restructuring of the vascular bed also develops in the lungs. Children with congenital heart defects experience retardation of general physical development.
Death occurs in the first days of life from hypoxia with particularly severe forms of defects or later from the development of heart failure. Depending on the degree of hypoxia, caused by a decrease in blood flow in the pulmonary circulation and the direction of blood flow through abnormal pathways between the pulmonary and systemic circulation, heart defects can be divided into two main types - blue and white. With blue type defects, there is a decrease in blood flow in the pulmonary circulation, hypoxia and the direction of blood flow along an abnormal path - from right to left. With white type defects, there is no hypoxia, the direction of blood flow is from left to right. However, this division is schematic and not always applicable to all types of congenital heart defects.
Congenital defects with impaired division of the heart cavities. Ventricular septal defects are common and depend on the growth retardation of one of the structures that form the septum, resulting in abnormal communication between the ventricles. More often, a defect is observed in the upper connective tissue (membranous) part of the septum. Blood flow through the defect is from left to right, so cyanosis and hypoxia are not observed (white type of defect). The degree of the defect can vary, up to the complete absence of the septum. With a significant defect, hypertrophy of the right ventricle of the heart develops, with a minor defect, no significant changes in hemodynamics occur.
The septum primum defect appears as a hole located directly above the ventricular valves; with a defect of the secondary septum, there is a wide open oval foramen, devoid of a valve. In both cases, blood flow occurs from left to right, hypoxia and cyanosis do not occur (white type of defect). Overflow of blood to the right half of the heart is accompanied by hypertrophy of the right ventricle and expansion of the trunk and branches of the pulmonary artery. The complete absence of the interventricular or interatrial septum leads to the development three-chambered heart- a severe defect, in which, however, during the period of compensation, complete mixing of arterial and venous blood is not observed, since the main flow of one or the other blood retains its direction and therefore the degree of hypoxia increases as decompensation progresses.
Congenital heart defects with impaired division of the truncus arteriosus. A common truncus arteriosus in the complete absence of division of the truncus arteriosus is rare. With this defect, one common arterial trunk originates from both ventricles, at the exit there are 4 semilunar valves or less; the defect is often combined with a ventricular septal defect. The pulmonary arteries depart from the common trunk not far from the valves, before the branches of the large vessels of the head and neck; they may be completely absent and then the lungs receive blood from the dilated bronchial arteries. With this defect, severe hypoxia and cyanosis are observed (blue type of defect), children are not viable.
Pulmonary artery stenosis and atresia observed when the septum of the arterial trunk is displaced to the right, often combined with a ventricular septal defect and other defects. When the pulmonary artery is significantly narrowed, blood enters the lungs through the ductus arteriosus and the dilating bronchial arteries. The defect is accompanied by hypoxia and severe cyanosis (blue type of defect).
Aortic stenosis and atresia are a consequence of displacement of the septum of the arterial trunk to the left. They are less common than septal displacement to the right and are often accompanied by hypoplasia of the left ventricle of the heart. In this case, a sharp degree of hypertrophy of the right ventricle of the heart, dilatation of the right atrium and a sharp general cyanosis are observed. Children are not viable.
Narrowing of the aortic isthmus (coarctation), up to its atresia, is compensated by the development of collateral circulation through the intercostal arteries, arteries of the chest and sharp hypertrophy of the left ventricle of the heart.
Patchy ductus arteriosus can be considered a defect if it is present with simultaneous expansion in children older than 3 months of life. The blood flow is from left to right (white type of defect). An isolated defect lends itself well to surgical correction.
Combined congenital heart defects. Among the combined defects, the triad, tetralogy and pentade of Fallot are more common. Triad of Fallot has 3 signs: ventricular septal defect, pulmonary artery stenosis and, as a consequence, right ventricular hypertrophy. Tetralogy of Fallot has 4 signs: ventricular septal defect, narrowing of the pulmonary artery, dextraposition of the aorta (displacement of the aortic mouth to the right) and hypertrophy of the right ventricle of the heart. Pentade of Fallot In addition to these four, it includes a 5th sign - atrial septal defect. Tetralogy of Fallot is the most common (40-50% of all congenital heart defects). With all defects of the Fallot type, blood flow from right to left, a decrease in blood flow in the pulmonary circulation, hypoxia and cyanosis (blue type of defects) are noted. More rare combined congenital defects include ventricular septal defect with stenosis of the left atrioventricular orifice ( Lutambashe disease), ventricular septal defect and aortic dextraposition ( Eisenmenger's disease) and a branch of the left coronary artery from the pulmonary trunk (Bland-White-Garland syndrome), primary pulmonary hypertension ( Aerz's disease), depending on the hypertrophy of the muscle layer pulmonary vessels(small arteries, veins and venules), etc.
Lecture for doctors "Urgent (urgent) situations in pediatric echocardiography, the correct diagnosis is life." Conducts a lecture at the Federal State Budgetary Institution Research Institute of Cardiology of the Russian Academy of Medical Sciences, Tomsk, A.A. Skolov.
CONGENITAL HEART DEFECTS
Congenital heart defects are found in 1% of children born alive. Most of these patients die in infancy and childhood, and only 5-15% survive to puberty. With timely surgical correction of congenital heart disease in childhood, the life expectancy of patients is significantly longer. Without surgical correction, patients with small VSD (ventricular septal defect), small ASD (atrial septal defect), moderate pulmonary stenosis, and patent ductus arteriosus usually survive to adulthood. large sizes, bicuspid aortic valve, minor stenosis of the aortic mouth, Ebstein anomaly, corrected by transposition of the great vessels. Patients with tetralogy of Fallot and a patent AV canal are less likely to survive into adulthood.
VENTRICULAR SEPTAL DEFECT
VSD (ventricular septal defect) is the presence of communication between the left and right ventricles, leading to pathological discharge of blood from one chamber of the heart to another. Defects can be located in the membranous (upper) part of the interventricular septum (75-80% of all defects), in the muscular part (10%), in the outflow tract of the right ventricle (supracrestal - 5%), in the inflow tract (atrioventricular septal defects - 15%). For defects located in the muscular part of the interventricular septum, the term “Tolochinov-Roger disease” is used.
Prevalence
VSD (ventricular septal defect) is the most common birth defect hearts in children and adolescents; it occurs less frequently in adults. This is due to the fact that in childhood, patients undergo surgical intervention; in some children, VSDs (ventricular septal defect) close on their own (the possibility of independent closure remains even in adulthood with small defects), and a significant proportion of children with large defects die. In adults, defects of small and medium size are usually detected. VSD (ventricular septal defect) can be combined with other congenital heart defects (in descending order of frequency): coarctation of the aorta, ASD (atrial septal defect), patent ductus arteriosus, subvalvular pulmonary artery stenosis, subvalvular aortic stenosis, mitral stenosis.
HEMODYNAMICS
In adults, VSDs (ventricular septal defect) persist due to the fact that they were either not identified in childhood or were not operated on in a timely manner (Fig. 9-1). Pathological changes in VSD (ventricular septal defect) depend on the size of the opening and the resistance of the pulmonary vessels.
Rice. 9-1. Anatomy and hemodynamics of VSD (ventricular septal defect). A - aorta; PA - pulmonary artery; LA - left atrium; LV - left ventricle; RA - right atrium; RV - right ventricle; IVC - inferior vena cava; SVC - superior vena cava. A short solid arrow indicates a ventricular septal defect.With a VSD (ventricular septal defect) of small size (less than 4-5 mm), the so-called restrictive defect, the resistance to blood flow through the shunt is high. Pulmonary blood flow increases slightly, pressure in the right ventricle and pulmonary vascular resistance also increase slightly.
With a medium-sized VSD (ventricular septal defect) (5-20 mm), there is a moderate increase in pressure in the right ventricle, usually not exceeding half the pressure in the left ventricle.
With a large VSD (greater than 20 mm, non-restrictive defect), there is no resistance to blood flow, and the pressure levels in the right and left ventricles are equal. An increase in blood volume in the right ventricle leads to increased pulmonary blood flow and increased pulmonary vascular resistance. With a significant increase in pulmonary vascular resistance, the discharge of blood from left to right through the defect decreases, and when pulmonary vascular resistance predominates over the resistance in the systemic circulation, a discharge of blood from right to left may occur with the appearance of cyanosis. With a large discharge of blood from left to right, pulmonary hypertension and irreversible sclerosis of the pulmonary arterioles (Eisenmenger syndrome) develop.
In some patients, perimembranous VSD (ventricular septal defect) or defects in the area of the right ventricular outflow tract can be combined with aortic regurgitation as a result of sagging of the aortic valve leaflet into the defect.
Complaints
Small-sized (restrictive) defects are asymptomatic. VSD (ventricular septal defect) of medium size leads to a lag in physical development and frequent infections respiratory tract. With large defects, as a rule, patients have signs of right and left ventricular failure: shortness of breath with physical activity, enlarged liver, swelling of the legs, orthopnea. When Eisenmenger syndrome occurs, patients begin to experience severe shortness of breath even with minor physical activity, chest pain without a clear connection with physical activity, hemoptysis, and episodes of loss of consciousness.
Inspection
Children with a medium-sized VSD (ventricular septal defect) are usually retarded in physical development, and they may have a cardiac hump. The discharge of blood from right to left leads to the appearance of changes in the fingers in the form of “drumsticks”, cyanosis, which increases with physical activity, and external signs of erythrocytosis (see Chapter 55 “Tumors of the Blood System”, Section 55.2 “Chronic Leukemia”).
Palpation
Systolic flutter is detected in the mid-sternum, associated with turbulent blood flow through the VSD (ventricular septal defect).
Auscultation hearts
The most characteristic sign is a rough systolic murmur along the left edge of the sternum with a maximum in the III-IV intercostal spaces on the left with irradiation to the right half of the chest. There is no clear correlation between the volume of the systolic murmur and the size of the VSD (ventricular septal defect) - a thin stream of blood through a small VSD may be accompanied by a loud noise (the saying “much ado about nothing” is true). A large VSD may not be accompanied by noise at all due to equalization of blood pressure in the left and right ventricles. In addition to noise, auscultation often reveals splitting of the second sound as a result of prolongation of the systole of the right ventricle. In the presence of a supracrestal VSD (ventricular septal defect), a diastolic murmur of concomitant aortic valve insufficiency is detected. The disappearance of noise with VSD is a sign not of improvement, but of deterioration of the condition, which appears as a result of equalization of pressure in the left and right ventricles.
Electrocardiography
The ECG with small defects is not changed. With a medium-sized VSD (ventricular septal defect), there are signs of hypertrophy of the left atrium and left ventricle, deviation of the electrical axis of the heart to the left. With a large VSD (ventricular septal defect), the ECG may show signs of hypertrophy of the left atrium and both ventricles.
X-ray study
For small defects, no changes are detected. With a significant discharge of blood from left to right, signs of enlargement of the right ventricle, increased vascular pattern due to an increase in pulmonary blood flow and pulmonary hypertension are revealed. With pulmonary hypertension, its characteristic radiological signs are observed.
Echocardiography
In 2D mode, a VSD (ventricular septal defect) can be directly visualized. Using the Doppler mode, turbulent blood flow from one ventricle to another is detected, the direction of discharge is assessed (from left to right or right to left), and the pressure in the right ventricle is determined by the pressure gradient between the ventricles.
Catheterization cavities hearts
Catheterization of the cavities of the heart makes it possible to detect high pressure in the pulmonary artery, the value of which is crucial for determining the tactics of patient management (operative or conservative). With catheterization, it is possible to determine the ratio of pulmonary blood flow and blood flow in the systemic circulation (normally the ratio is less than 1.5:1).
TREATMENT
VSD (ventricular septal defect) of small size usually does not require surgical treatment due to its favorable course. Surgical treatment of VSD (ventricular septal defect) is also not performed if normal pressure in the pulmonary artery (the ratio of pulmonary blood flow to blood flow in the systemic circulation is less than 1.5-2:1). Surgical treatment (VSD closure) is indicated for medium or large VSD (ventricular septal defect) with a pulmonary to systemic blood flow ratio of more than 1.5:1 or 2:1 in the absence of high pulmonary hypertension. If the resistance of the pulmonary vessels is 1/3 or less of the resistance in the systemic circulation, then progression of pulmonary hypertension after surgery is usually not observed. If there is a moderate or pronounced increase in pulmonary vascular resistance before surgery after radical correction of the defect, pulmonary hypertension persists (it may even progress). With large defects and increased pressure in the pulmonary artery, the result of surgical treatment is unpredictable, since, despite the closure of the defect, changes in the pulmonary vessels persist.
It is necessary to carry out prevention of infective endocarditis (see Chapter 6 "Infective endocarditis").
FORECAST
The prognosis is usually favorable with timely surgical treatment. The risk of infective endocarditis with VSD (ventricular septal defect) is 4%, which requires timely prevention of this complication.
Tetralogy of Fallot
Tetralogy of Fallot is a congenital heart defect characterized by the presence of four components: 1) a large, high-lying VSD (ventricular septal defect); 2) pulmonary artery stenosis; 3) dextroposition of the aorta; 4) compensatory hypertrophy of the right ventricle.
Prevalence
Tetralogy of Fallot accounts for 12-14% of all congenital heart defects.
HEMODYNAMICS
In tetralogy of Fallot, the aorta lies over a large VSD (ventricular septal defect) and over both ventricles, resulting in equal systolic pressures in the right and left ventricles (Figure 9-2). The main hemodynamic factor is the relationship between the resistance to blood flow in the aorta and in the stenotic pulmonary artery.
With little resistance in the pulmonary vessels, pulmonary blood flow may be twice that of the systemic circulation, and arterial oxygen saturation may be normal (acyanotic tetralogy of Fallot).
With significant resistance to pulmonary blood flow, blood shunts from right to left, resulting in cyanosis and polycythemia.
Pulmonary artery stenosis can be infundibular or combined, less often valvular (for more details, see Chapter 8 “Acquired heart defects”).
During exercise, blood flow to the heart increases, but blood flow through the pulmonary circulation does not increase due to the stenotic pulmonary artery, and excess blood is dumped into the aorta through the VSD (ventricular septal defect), so cyanosis increases. Hypertrophy occurs, which leads to increased cyanosis. Right ventricular hypertrophy develops as a result of constantly overcoming an obstacle in the form of pulmonary artery stenosis. As a result of hypoxia, compensatory polycythemia develops - the number of red blood cells and hemoglobin increases. Anastomoses develop between the bronchial arteries and the branches of the pulmonary artery. In 25% of patients, a right-sided location of the aortic arch and descending aorta is found.
CLINICAL PICTURE AND DIAGNOSTICS
Complaints
The main complaint of adults with tetralogy of Fallot is shortness of breath. In addition, heart pain unrelated to physical activity and palpitations may be bothersome. Patients are prone to pulmonary infections (bronchitis and pneumonia).
Inspection
Cyanosis is noted, the severity of which may vary. Sometimes the cyanosis is so pronounced that not only the skin and lips, but also the oral mucosa and conjunctiva. Characterized by a lag in physical development, changes in the fingers (“drumsticks”), nails (“watch glasses”).
Palpation
Systolic tremors are detected in the second intercostal space to the left of the sternum above the area of pulmonary artery stenosis.
Auscultation hearts
Listen to the rough systolic murmur of pulmonary artery stenosis in the II-III intercostal spaces to the left of the sternum. The second tone above the pulmonary artery is weakened.
Laboratory research
Complete blood count: high erythrocytosis, increased hemoglobin content, ESR sharply reduced (to 0-2 mm/h).
Electrocardiography
The electrical axis of the heart is usually shifted to the right (angle α from +90° to +210°), signs of right ventricular hypertrophy are noted.
Echocardiography
Echocardiography can detect the anatomical components of the tetralogy of Fallot.
X-ray study
Increased transparency of the pulmonary fields is noted due to a decrease in blood supply to the lungs. The contours of the heart have a specific shape of a “wooden clog shoe”: a reduced arch of the pulmonary artery, an emphasized “waist of the heart”, a rounded and raised apex of the heart above the diaphragm. The aortic arch may be on the right.
COMPLICATIONS
The most common occurrences are strokes, pulmonary embolism, severe heart failure, infective endocarditis, brain abscesses, and various arrhythmias.
TREATMENT
The only method of treatment is surgical (radical surgery - plastic surgery of the defect, elimination of pulmonary artery stenosis and displacement of the aorta). Sometimes surgery consists of two stages (the first stage is to eliminate pulmonary artery stenosis, and the second is to perform VSD (ventricular septal defect) plastic surgery).
FORECAST
In the absence of surgical treatment, 3% of patients with tetralogy of Fallot survive to 40 years of age. Deaths occur due to strokes, brain abscesses, severe heart failure, infective endocarditis, and arrhythmias.
PENTAD OF FALLOT
Pentade of Fallot is a congenital heart defect consisting of five components: four signs of tetralogy of Fallot and ASD (atrial septal defect). Hemodynamics, clinical picture, diagnosis and treatment are similar to those of tetralogy of Fallot and ASD (atrial septal defect).
ATRIAL SEPTAL DEFECT
ASD (atrial septal defect) is the presence of communication between the left and right atria, leading to pathological discharge of blood (shunting) from one chamber of the heart to another.
Classification
According to the anatomical location, primary and secondary ASD (atrial septal defect), as well as a venous sinus defect are distinguished.
Primary ASD (atrial septal defect) is located below the fossa ovale and is part of a congenital heart defect called patent atrioventricular canal.
Secondary ASD (atrial septal defect) is located in the area of the fossa ovale.
A sinus venosus defect is a communication between the superior vena cava and both atria, located above the normal interatrial septum.
ASD (atrial septal defect) of other localizations (for example, coronary sinus) are also distinguished, but they are extremely rare.
Prevalence
ASD (atrial septal defect) accounts for about 30% of all congenital heart defects. It is more often found in women. 75% of ASDs (atrial septal defect) are secondary, 20% are primary, 5% are venous sinus defects. This defect is often combined with others - pulmonary stenosis, abnormal drainage of the pulmonary veins, mitral valve prolapse. ASD (atrial septal defect) can be multiple.
HEMODYNAMICS
Shunting blood from left to right leads to diastolic overload of the right ventricle and increased blood flow in the pulmonary artery (Fig. 9-3). The direction and volume of blood discharged through the defect depends on the size of the defect, the pressure gradient between the atria and the compliance (extensibility) of the ventricles.
With restrictive ASD (atrial septal defect), when the area of the defect less area atrioventricular orifice, there is a pressure gradient between the atria and blood discharge from left to right.
With a non-restrictive ASD (large in size), there is no pressure gradient between the atria and the volume of blood shunted through the defect is regulated by the compliance (extensibility) of the ventricles. The right ventricle is more compliant (so pressure in the right atrium drops faster than in the left), and blood shunts from left to right, causing dilation of the right chambers of the heart and increasing blood flow through the pulmonary artery.
In contrast to VSD (ventricular septal defect), pulmonary artery pressure and pulmonary vascular resistance with ASD (atrial septal defect) for a long time remain low due to the low pressure gradient between the atria. This explains the fact that ASD (atrial septal defect) in childhood usually remains unrecognized. The clinical picture of ASD (atrial septal defect) manifests itself with age (over 15-20 years) as a result of an increase in pressure in the pulmonary artery and the appearance of other complications - heart rhythm disturbances, right ventricular failure [in the latter case, the risk of pulmonary embolism and arteries of the great circle (paradoxical embolism) high]. With age, with large ASD (atrial septal defect), hypertension may appear due to an increase in peripheral vascular resistance as a result of anatomical changes in the pulmonary vessels, and blood discharge gradually becomes bidirectional. Less commonly, blood discharge may occur from right to left.
CLINICAL PICTURE AND DIAGNOSTICS
Complaints
Complaints in patients with ASD (atrial septal defect) long time are missing. Anamnestic reveals frequent illnesses respiratory tract - bronchitis, pneumonia. Shortness of breath may be a concern, occurring initially with exertion and then at rest, fast fatiguability. After 30 years, the disease progresses: palpitations (supraventricular arrhythmias and atrial fibrillation), signs of pulmonary hypertension (see Chapter 14 “Pulmonary Hypertension”) and heart failure of the right ventricular type develop.
Inspection
The examination allows us to determine some delay in physical development. The appearance of cyanosis and changes in the terminal phalanges of the fingers in the form of “drum sticks” and nails in the form of “watch glasses” indicate a change in the direction of blood discharge from right to left.
Palpation
The pulsation of the pulmonary artery (in the presence of pulmonary hypertension) is determined in the second intercostal space to the left of the sternum.
Auscultation hearts
When the defect is small, no auscultatory changes are detected, so usually an ASD (atrial septal defect) is diagnosed when signs of pulmonary hypertension appear.
The first heart sound is not changed. The second tone is split due to a significant lag in the pulmonary component of the second sound as a result of the flow of a large volume of blood through the right parts of the heart (extension of right ventricular systole). This splitting is fixed, i.e. does not depend on the phases of breathing.
A systolic murmur is heard over the pulmonary artery as a result of the ejection of an increased volume of blood from the right ventricle. In case of primary ASD (atrial septal defect), a systolic murmur of relative insufficiency of the mitral and tricuspid valves is also heard at the apex of the heart. A low-frequency diastolic murmur may be heard over the tricuspid valve due to increased blood flow through the tricuspid valve.
With an increase in pulmonary vascular resistance and a decrease in blood discharge from left to right, the auscultatory picture changes. The systolic murmur over the pulmonary artery and the pulmonary component of the second sound intensify; both components of the second sound can merge. In addition, a diastolic murmur of pulmonary valve insufficiency appears.
Electrocardiography
With secondary ASD (atrial septal defect), complexes are noted rSR’ in the right chest leads(as a manifestation of delayed activation of the posterobasal sections of the interventricular septum and expansion of the outflow tract of the right ventricle), deviation of the electrical axis of the heart to the right (with hypertrophy and dilatation of the right ventricle). In case of a venous sinus defect, first degree AV block and lower atrial rhythm are observed. Heart rhythm disturbances in the form of supraventricular arrhythmias and atrial fibrillation are characteristic.
X-ray study
X-ray examination reveals dilatation of the right atrium and right ventricle, dilatation of the trunk of the pulmonary artery and its two branches, the symptom of “dancing the roots of the lungs” (increased pulsation as a result of increased pulmonary blood flow due to blood discharge).
Echocardiography
Echocardiography (Fig. 9-4) helps detect dilatation of the right ventricle, right atrium, and paradoxical motion of the interventricular septum. If the defect size is sufficient, it can be detected in two-dimensional mode, especially clearly in the subxiphoid position (when the position of the interatrial septum is perpendicular to the ultrasound beam). The presence of a defect is confirmed by Doppler ultrasound, which makes it possible to identify the turbulent flow of shunted blood from the left atrium to the right or, conversely, through the interatrial septum. Signs of pulmonary hypertension are also detected.
Rice. 9-4. EchoCG for ASD (two-dimensional mode, four-chamber position). 1 - right ventricle; 2 - left ventricle; 3 - left atrium; 4 - atrial septal defect; 5 - right atrium.
Catheterization cavities hearts
Catheterization of the cardiac cavities is performed to determine the severity of pulmonary hypertension.
TREATMENT
In the absence of severe pulmonary hypertension, surgical treatment is performed - ASD repair (atrial septal defect). If there are symptoms of heart failure, therapy with cardiac glycosides, diuretics, and ACE inhibitors is necessary (for more information, see Chapter 11 “Heart Failure”). In patients with primary ASD and venous sinus defect, prophylaxis of infective endocarditis is recommended (see Chapter 6 “Infective endocarditis”).
FORECAST
With timely surgical treatment, the prognosis is favorable. In non-operated patients, deaths before the age of 20 are rare, but after 40 years the mortality rate reaches 6% per year. The main complications of ASD (atrial septal defect) are atrial fibrillation, heart failure, and rarely paradoxical embolism. Infective endocarditis with secondary ASD occurs very rarely. In cases of small ASD, patients live to a ripe old age.
OPEN DUCT ARTERIUS
Patent ductus arteriosus is a defect characterized by non-closure of the vessel between the pulmonary artery and the aorta (ductus arteriosus) within 8 weeks after birth; The duct functions in the prenatal period, but its non-closure leads to hemodynamic disturbances.
Prevalence
Patent ductus arteriosus is observed in the general population with an incidence of 0.3%. It accounts for 10-18% of all congenital heart defects.
HEMODYNAMICS
Most often, the ductus arteriosus connects the pulmonary artery and the descending aorta below the origin of the left subclavian artery; less often, it connects the pulmonary artery and the descending aorta above the origin of the left subclavian artery (Fig. 9-5). 2-3 days (less often 8 weeks) after birth, the duct closes. In premature babies, with fetal hypoxia, fetal rubella (in the first trimester of pregnancy), the duct remains open. There is a discharge (shunting) of blood from the descending aorta into the trunk of the pulmonary artery. Further manifestations of the defect depend on the diameter and length of the patent ductus arteriosus and the resistance to blood flow in the duct itself.
Rice. 9-5. Anatomy and hemodynamics of patent ductus arteriosus. A - aorta; PA - pulmonary artery; LA - left atrium; LV - left ventricle; RA - right atrium; RV - right ventricle; IVC - inferior vena cava; SVC - superior vena cava. The solid part of the arrow indicates the pathological flow of blood from the aorta to the pulmonary arteries.
With a small duct size and high shunt resistance, the volume of discharged blood is insignificant. The flow of excess blood into the pulmonary artery, left atrium and left ventricle is also small. The direction of blood discharge during systole and diastole remains constant (continuous) - from the left (from the aorta) to the right (to the pulmonary artery).
With a large diameter of the duct, a significant excess amount of blood will flow into the pulmonary artery, leading to an increase in pressure in it (pulmonary hypertension) and overloading the left atrium and left ventricle with volume (the consequence of this is dilatation and hypertrophy of the left ventricle). Over time, irreversible changes in the pulmonary vessels (Eisenmenger syndrome) and heart failure develop. Subsequently, the pressure in the aorta and pulmonary artery is equalized, and then in the pulmonary artery it becomes higher than in the aorta. This leads to a change in the direction of blood discharge - from the right (from the pulmonary artery) to the left (to the aorta). Subsequently, right ventricular failure occurs.
CLINICAL PICTURE AND DIAGNOSTICS
The manifestations of the defect depend on the size of the patent ductus arteriosus. A patent ductus arteriosus with a small discharge of blood may not manifest itself in childhood and may manifest itself with age as fatigue and shortness of breath during physical exertion. At large volume discharged blood since childhood, there are complaints of shortness of breath during physical exertion, signs of orthopnea, cardiac asthma, pain in the right hypochondrium due to liver enlargement, swelling of the legs, cyanosis of the legs (as a result of discharge of blood from right to left into the descending aorta), cyanosis of the left arm (with an open arterial duct above the origin of the left subclavian artery).
With a small volume of blood discharge from left to right external signs there is no vice. When blood is discharged from right to left, cyanosis of the legs appears, changes in the toes in the form of “drumsticks”, changes in the fingers of the left hand in the form of “drumsticks”.
Palpation
With intense blood discharge from left to right, systolic trembling of the chest is determined above the pulmonary artery and suprasternally (in the jugular fossa).
Auscultation hearts
The typical auscultatory manifestation of a patent ductus arteriosus is a continuous systole-diastolic (“machine”) murmur due to constant unidirectional blood flow from the aorta to the pulmonary artery. This noise is high-frequency, intensifies towards the second tone, is better heard under the left collarbone and radiates to the back. In addition, a mid-diastolic murmur may be heard at the apex of the heart due to increased blood flow through the left atrioventricular orifice. The sonority of the second tone can be difficult to determine due to the loud noise. When the pressure in the aorta and pulmonary artery is equalized, the noise from continuous systole-diastolic turns into systolic, and then disappears completely. In this situation, the accent of the second tone over the pulmonary artery begins to clearly emerge (a sign of the development of pulmonary hypertension).
Electrocardiography
If the blood discharge is small, pathological changes are not detected. When the left parts of the heart are overloaded with a large volume of excess blood, signs of hypertrophy of the left atrium and left ventricle are noted. Against the background of severe pulmonary hypertension, the ECG reveals signs of hypertrophy of the right ventricle.
Echocardiography
With significant sizes of the patent ductus arteriosus, dilatation of the left atrium and left ventricle is observed. A large patent ductus arteriosus can be detected in two dimensions. In Doppler mode, a turbulent systole-diastolic flow is determined in the pulmonary artery, regardless of the size of the duct.
X-ray study
If the shunt is small, the radiographic picture is usually unchanged. With pronounced blood discharge, an enlargement of the left chambers of the heart and signs of pulmonary hypertension (bulging of the pulmonary artery trunk) are detected.
TREATMENT
If signs of heart failure appear, cardiac glycosides and diuretics are prescribed (see Chapter 11 “Heart failure”). It is recommended to prevent infectious endarteritis before and for six months after surgical correction of the defect (see Chapter 6 “Infective endocarditis”).
Surgical treatment in the form of ligation of the patent ductus arteriosus or occlusion of its lumen must be carried out before the development of irreversible changes in the pulmonary vessels. After surgical treatment, signs of pulmonary hypertension may persist or even progress.
COMPLICATIONS
With an open ductus arteriosus, complications may occur: infectious endarteritis, pulmonary embolism, ductal aneurysm, its dissection and rupture, calcification of the duct, heart failure. Infectious endarteritis usually develops in the pulmonary artery opposite the open ductus arteriosus as a result of constant trauma to the wall of the pulmonary artery with a stream of blood. The incidence of infectious endarteritis reaches 30%.
FORECAST
Timely surgery eliminates the pathological discharge of blood from the aorta into the pulmonary artery, although signs of pulmonary hypertension may persist throughout life. The average life expectancy without surgical treatment is 39 years.
To diagnose coarctation of the aorta, correct measurement of blood pressure in the legs is important. To do this, the patient is placed on his stomach, a cuff is placed on the lower third of the thigh and auscultation is performed in the popliteal fossa using a technique similar to that when measuring pressure in the arms (with determination of systolic and diastolic levels). Normally, the pressure in the legs is 20-30 mm Hg. higher than on the hands. With coarctation of the aorta, the pressure in the legs is significantly reduced or not detected. Diagnostic sign Coarctation of the aorta is considered to be a difference in systolic (or mean) blood pressure in the arms and legs of more than 10-20 mmHg. Approximately equal pressure is often noted on the arms and legs, but after physical activity (treadmill) a significant difference is determined. The difference in systolic blood pressure on the left and right hands indicates that the origin of one of the subclavian arteries is located above or below the obstruction.
Palpation
Determine the absence or significant weakening of the pulse in the legs. You can detect increased pulsating collaterals in the intercostal spaces, in the interscapular space.
Auscultation hearts
The accent of the second tone is detected over the aorta due to high blood pressure. Systolic murmur is characteristic at the Botkin-Erb point, as well as under the left clavicle, in the interscapular space and on the vessels of the neck. With developed collaterals, a systolic murmur is heard over the intercostal arteries. With further progression of hemodynamic disorders, a continuous (systolic-diastolic) murmur is heard.
Electrocardiography
Signs of left ventricular hypertrophy are detected.
Echocardiography
A suprasternal examination of the aorta in two-dimensional mode shows signs of narrowing. With a Doppler study, turbulent systolic flow is determined below the site of narrowing and the pressure gradient between the dilated and narrowed parts of the aorta is calculated, which is often important when deciding on surgical treatment.
X-ray study
With the long-term existence of collaterals, usuration of the lower parts of the ribs is detected as a result of compression by their dilated and tortuous intercostal arteries. To clarify the diagnosis, aortography is performed, which accurately identifies the location and degree of coarctation.
TREATMENT
A radical method of treating aortic coarctation is surgical excision narrowed area. Drug therapy is carried out depending on clinical manifestations vice. For symptoms of heart failure, cardiac glycosides, diuretics, and ACE inhibitors are prescribed (for more details, see Chapter 11 “Heart Failure”). Treatment for hypertension may be necessary.
PROGNOSIS AND COMPLICATIONS
Without surgical treatment, 75% of patients die by age 50. As a result of high blood pressure, typical complications may develop: strokes, kidney failure. An atypical complication of hypertension is the development of neurological disorders (for example, lower paraparesis, urinary dysfunction) due to compression of the roots by dilated intercostal arteries spinal cord. Rare complications include infectious endoaortitis and rupture of the dilated aorta.
CONGENITAL AORTIC STENOSIS
Congenital stenosis of the aortic mouth is a narrowing of the outflow tract of the left ventricle in the area of the aortic valve. Depending on the level of obstruction, stenosis can be valvular, subvalvular, or supravalvular.
Prevalence
Congenital aortic stenosis accounts for 6% of all congenital heart defects. Valve stenosis is most often noted (80%), less often subvalvular and supravalvular. In men, aortic stenosis is observed 4 times more often than in women.
HEMODYNAMICS
Valvular stenosis (see Fig. 9-7). Most often, the aortic valve is bicuspid, with the opening located eccentrically. Sometimes the valve consists of one leaf. Less commonly, the valve consists of three leaflets, fused together by one or two adhesions.
With subvalvular stenosis, three types of changes are noted: a discrete membrane under the aortic valves, a tunnel, muscle narrowing (subaortic hypertrophic cardiomyopathy, see Chapter 12 “Cardiomyopathies and Myocarditis”).
Supravalvular stenosis of the aortic ostium can be in the form of a membrane or hypoplasia of the ascending aorta. A sign of hypoplasia of the ascending aorta is considered to be a ratio of the diameter of the aortic arch to the diameter of the ascending aorta of less than 0.7. Often supravalvular stenosis of the aortic mouth is combined with stenosis of the branches of the pulmonary artery.
Supravalvular stenosis of the aortic mouth in combination with mental retardation called Williams syndrome.
Aortic stenosis is often combined with other congenital heart defects - VSD (ventricular septal defect), ASD (atrial septal defect), patent ductus arteriosus, coarctation of the aorta.
In any case, an obstacle to blood flow is created and the changes described in Chapter 8 “Acquired heart defects” develop. Over time, valve calcification develops. The development of poststenotic expansion of the aorta is characteristic.
CLINICAL PICTURE AND DIAGNOSTICS
Complaints
Most patients with minor stenosis do not complain. The appearance of complaints indicates severe stenosis of the aortic mouth. There are complaints of shortness of breath during exercise, fatigue (due to reduced cardiac output), fainting (as a result of cerebral hypoperfusion), and chest pain during exercise (due to myocardial hypoperfusion). Sudden cardiac death may occur, but in most cases this is preceded by complaints or changes in the ECG.
Inspection, percussion
See "Aortic Stenosis" in Chapter 8, "Acquired Heart Defects."
Palpation
Systolic vibration is determined along the right edge of the upper part of the sternum and over the carotid arteries. When the peak systolic pressure gradient is less than 30 mmHg. (according to echocardiography) tremors are not detected. Low pulse pressure (less than 20 mmHg) indicates significant severity of aortic stenosis. With valvular stenosis, a small slow pulse is detected.
Auscultation hearts
Characteristic is a weakening of the second tone or its complete disappearance due to the weakening (disappearance) of the aortic component. With supravalvular stenosis of the aortic mouth, the second sound is preserved. With valvular stenosis of the aortic mouth, an early systolic click is heard at the apex of the heart, which is absent in supra- and subvalvular stenoses. It disappears with severe valvular stenosis of the aortic mouth.
The main auscultatory sign of aortic stenosis is a rough systolic murmur with a maximum in the second intercostal space on the right and irradiation to carotid arteries, sometimes along the left edge of the sternum to the apex of the heart. With subvalvular stenosis of the aortic mouth, differences in auscultatory manifestations are observed: an early systolic click is not heard, an early diastolic murmur of aortic valve insufficiency is noted (in 50% of patients).
Electrocardiography
With valvular stenosis, signs of left ventricular hypertrophy are detected. With supravalvular stenosis of the aortic mouth, the ECG may not be changed. With subvalvular stenosis (in the case of subaortic hypertrophic cardiomyopathy), pathological waves may be detected Q(narrow and deep).
Echocardiography
In two-dimensional mode, the level and nature of obstruction of the aortic opening (valvular, subvalvular, supravalvular) are determined. In Doppler mode, the peak systolic pressure gradient (the maximum pressure gradient when the aortic valve leaflets open) and the degree of stenosis of the aortic ostium are assessed.
When the peak systolic pressure gradient (with normal cardiac output) is more than 65 mmHg. or the area of the aortic opening is less than 0.5 cm 2 / m 2 (normally the area of the aortic opening is 2 cm 2 / m 2), stenosis of the aortic orifice is considered severe.
Peak systolic pressure gradient 35-65 mm Hg. or an area of the aortic opening of 0.5-0.8 cm 2 / m 2 is considered as stenosis of the aortic mouth medium degree.
When the peak systolic pressure gradient is less than 35 mm Hg. or the area of the aortic opening is more than 0.9 cm 2 / m 2, stenosis of the aortic mouth is considered minor.
These indicators are informative only if left ventricular function is preserved and there is no aortic regurgitation.
X-ray study
Poststenotic dilatation of the aorta is detected. With subvalvular stenosis of the aortic mouth, there is no post-stenotic dilatation of the aorta. It is possible to detect calcifications in the projection of the aortic valve.
TREATMENT
In the absence of calcification, valvotomy or excision of a discrete membrane is performed. With pronounced fibrotic changes aortic valve replacement is indicated.
PROGNOSIS AND COMPLICATIONS
Aortic stenosis usually progresses regardless of the level of obstruction (valvular, supravalvular, subvalvular). The risk of developing infective endocarditis is 27 cases per 10,000 patients with aortic stenosis per year. With a pressure gradient of more than 50 mm Hg. the risk of infective endocarditis increases 3 times. With aortic stenosis, sudden cardiac death is possible, especially during physical exertion. The risk of sudden cardiac death increases with increasing pressure gradient - it is higher in patients with aortic stenosis with a pressure gradient of more than 50 mm Hg.
PULMONARY ARTERY STENOSIS
Pulmonary stenosis is a narrowing of the outflow tract of the right ventricle in the area of the pulmonary valve.
Prevalence
Isolated pulmonary artery stenosis accounts for 8-12% of all congenital heart defects. In most cases, this is valvular stenosis (the third most common congenital heart defect), but it can also be combined (in combination with subvalvular, supravalvular stenoses, and other congenital heart defects).
HEMODYNAMICS
The narrowing can be valvular (80-90% of cases), subvalvular, supravalvular.
With valvular stenosis, the pulmonary valve can be unicuspid, bicuspid or tricuspid. Poststenotic dilatation of the pulmonary artery trunk is characteristic.
Isolated subvalvular stenosis is characterized by infundibular (funnel-shaped) narrowing of the right ventricular outflow tract and an abnormal muscle band that prevents the ejection of blood from the right ventricle (both options are usually combined with VSD (ventricular septal defect)).
Isolated supravalvular stenosis can be in the form of localized stenosis, complete or incomplete membrane, diffuse hypoplasia, multiple peripheral pulmonary artery stenoses.
When the pulmonary trunk narrows, an increase in the pressure gradient between the right ventricle and the pulmonary artery occurs. Due to an obstruction in the path of blood flow, hypertrophy of the right ventricle occurs, and then its failure. This leads to increased pressure in the right atrium, opening of the foramen ovale and shunting of blood from right to left with the development of cyanosis and right ventricular failure. In 25% of patients, pulmonary artery stenosis is combined with a secondary ASD (atrial septal defect).
CLINICAL PICTURE AND DIAGNOSTICS
Complaints
Mild pulmonary stenosis is asymptomatic in most cases. With severe stenosis, rapid fatigue, shortness of breath and chest pain during physical activity, cyanosis, dizziness and fainting appear. Dyspnea with pulmonary stenosis occurs as a result of inadequate perfusion of working peripheral muscles, causing reflex ventilation of the lungs. Cyanosis in pulmonary artery stenosis can be of either peripheral (the result of low cardiac output) or central (the result of blood discharge through the patent foramen ovale) origin.
Inspection
You can detect pulsation of the enlarged right ventricle in the epigastric region. When tricuspid valve insufficiency occurs as a result of decompensation of the right ventricle, swelling and pulsation of the neck veins are detected. Also see the sections “Pulmonary Stenosis” and “Tricuspid Valve Insufficiency” in Chapter 8, “Acquired Heart Defects.”
Palpation
Systolic tremor is determined in the second intercostal space to the left of the sternum.
Auscultation hearts
The second tone with slight and moderate valvular stenosis of the pulmonary artery is not changed or is slightly weakened due to the lesser participation of the pulmonary component in its formation. With severe stenosis and a significant increase in pressure in the right ventricle, the second sound may disappear completely. With infundibular and supravalvular stenoses of the pulmonary artery, tone II does not change.
With valvular stenosis of the pulmonary artery in the second intercostal space to the left of the sternum, an early systolic click is heard at the moment of maximum opening of the pulmonary valve leaflets. The systolic click increases with exhalation. At other levels of stenosis (supravalvular, subvalvular), a systolic click is not heard.
The main auscultatory manifestation of pulmonary artery stenosis is a rough systolic murmur in the second intercostal space to the left of the sternum with irradiation under the left clavicle and into the back. With supravalvular stenosis, the noise radiates to the left axillary region and back. The duration of the systolic murmur and its peak correlate with the degree of stenosis: with moderate stenosis, the peak of the murmur is noted in the middle of systole, and its end is before the aortic component of the second sound; with severe stenosis, the systolic murmur is later and continues after the aortic component of the second sound; with supravalvular stenosis or peripheral stenosis of the branches of the pulmonary artery, there is a systolic or continuous murmur with irradiation into the pulmonary fields.
Electrocardiography
With minor stenosis of the pulmonary artery, no changes are detected on the ECG. With moderate and severe stenosis, signs of right ventricular hypertrophy are found. With severe pulmonary artery stenosis, signs of hypertrophy (dilatation) of the right atrium appear. Supraventricular arrhythmias may occur.
Echocardiography
Normally, the area of the valve opening of the pulmonary artery is 2 cm 2 / m 2. In case of valvular pulmonary artery stenosis, a dome-shaped protrusion of the thickened leaflets of the pulmonary artery valve into the trunk of the pulmonary artery during systole of the right ventricle is detected in two-dimensional mode. Thickening of the wall (hypertrophy) of the right ventricle is characteristic. Other levels of pulmonary artery obstruction and their nature are also determined. The Doppler mode allows you to determine the degree of obstruction by the pressure gradient between the right ventricle and the pulmonary trunk. Mild pulmonary stenosis is diagnosed when the peak systolic pressure gradient is less than 50 mmHg. Pressure gradient 50-80 mm Hg. corresponds to a moderate degree of stenosis. With a pressure gradient of more than 80 mm Hg. speak of severe pulmonary artery stenosis (the gradient can reach 150 mm Hg or more in cases of severe stenosis).
X-ray study
With valvular stenosis of the pulmonary artery, a post-stenotic expansion of its trunk is detected. It is absent in supra- and subvalvular stenoses. Characteristic depletion of the pulmonary pattern.
Catheterization cavities hearts
Catheterization of the cardiac cavities allows you to accurately determine the degree of stenosis by the pressure gradient between the right ventricle and the pulmonary artery.
TREATMENT AND PROGNOSIS
Minor and moderate valvular stenosis of the pulmonary artery usually proceeds favorably and does not require active intervention. Subvalvular muscular stenosis progresses more significantly. Supravalvular stenosis usually progresses slowly. When the pressure gradient between the right ventricle and the pulmonary artery increases by more than 50 mm Hg. in case of valvular stenosis, valvuloplasty is performed (after valvotomy, 50-60% of patients develop pulmonary valve insufficiency). If heart failure occurs, it is treated (see Chapter 11 “Heart failure”). Prevention of infective endocarditis is recommended (see Chapter 6 “Infective endocarditis”), since the risk of its development is quite high.
EBSTEIN ANOMALY
Ebstein's anomaly is the location of the posterior and septal leaflets of the tricuspid valve at the apex of the right ventricle, leading to an enlargement of the right atrium cavity and a decrease in the right ventricular cavity. Epstein anomaly accounts for about 1% of all congenital heart defects. The occurrence of this defect is associated with the intake of lithium into the fetus during pregnancy.
HEMODYNAMICS
The displacement of the attachment site of the two leaflets of the tricuspid valve into the cavity of the right ventricle leads to the fact that the latter is divided into the supravalvular part, which is combined with the cavity of the right atrium into a single chamber (atrialization of the right ventricular cavity) and a reduced subvalvular part (the cavity of the right ventricle itself) (Fig. 9-8). A decrease in the cavity of the right ventricle leads to a decrease in stroke volume and a decrease in pulmonary blood flow. Since the right atrium consists of two parts (the right atrium itself and part of the right ventricle), the electrical and mechanical processes in it are different (not synchronized). During right atrium systole, the atrialized portion of the right ventricle is in diastole. This results in decreased blood flow to the right ventricle. During right ventricular systole, right atrial diastole occurs with incomplete closure of the tricuspid valve, which results in the displacement of blood in the atrialized portion of the right ventricle back into the main portion of the right atrium. There is a significant expansion of the fibrous ring of the tricuspid valve, pronounced dilatation of the right atrium (it can hold more than 1 liter of blood), an increase in pressure in it and a retrograde increase in pressure in the inferior and superior vena cava. The expansion of the cavity of the right atrium and the increase in pressure in it help to keep the oval opening open and a compensatory decrease in pressure due to the discharge of blood from right to left.
CLINICAL PICTURE AND DIAGNOSTICS
Complaints
Patients may complain of shortness of breath during exercise, palpitations due to supraventricular arrhythmias (observed in 25-30% of patients and often cause sudden cardiac death).
Inspection
Cyanosis is detected when blood is shunted from right to left, signs of tricuspid valve insufficiency (see Chapter 8 “Acquired heart defects”). Characteristic signs of right ventricular failure (dilation and pulsation of the veins of the neck, enlarged liver and edema).
Percussion
The boundaries of relative cardiac dullness are shifted to the right due to the enlarged right atrium.
Auscultation hearts
The first heart sound is usually split. The appearance of III and IV heart sounds is possible. Systolic murmur is characteristic in the III-IV intercostal spaces to the left of the sternum and at the apex due to tricuspid valve insufficiency. Sometimes a diastolic murmur is heard associated with relative stenosis of the right atrioventricular orifice.
Electrocardiography
An ECG may show signs of Wolff-Parkinson-White syndrome in 20% of patients (more often there are right-sided accessory pathways). Characteristic signs are of right bundle branch block, the presence of signs of right atrium hypertrophy in combination with 1st degree AV block.
Echocardiography
All anatomical signs of Ebstein's anomaly are identified (Fig. 9-9): abnormal location of the tricuspid valve leaflets (their dystopia), enlarged right atrium, small right ventricle. In Doppler mode, tricuspid valve insufficiency is detected.
X-ray study
Cardiomegaly is noted (characteristic of the spherical shape of the heart shadow) with increased transparency of the pulmonary fields.
TREATMENT
When symptoms of heart failure appear, cardiac glycosides (contraindicated in the presence of Wolff-Parkinson-White syndrome) and diuretics are prescribed. Surgical treatment consists of tricuspid valve replacement or reconstruction.
FORECAST
Main reasons fatal outcome: severe heart failure, thromboembolism, brain abscesses, infective endocarditis.
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Anatomical disorders in the structure of the myocardium, its valves and vessels that arose before the birth of the child are called congenital heart defects. They cause circulatory disturbances inside the organ and throughout circulatory system.
The manifestations depend on the type of heart defect - bluish or pale skin color, heart murmurs, slow development of children. They are usually accompanied by insufficiency of the cardiovascular and pulmonary systems. The most common method of treatment is surgery.
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Causes of heart defects
The formation of heart defects can be caused by disturbances in the structure of chromosomes, gene mutations, exposure to external harmful factors, but more often all these reasons influence simultaneously.
Etiology of CHD (congenital heart defects) When a section of chromosomes or an altered gene sequence is removed or duplicated, defects in the septa between the atria, ventricles, or a combination of both occur. When genes are rearranged in the sex chromosomes, narrowing of the aortic lumen is more often diagnosed.
Genes associated with the formation of various congenital heart defects: ASD - atrial septal defect, AVB - atrioventricular block; AVSD—atrioventricular septal defect; DORV - double outlet of vessels from the right ventricle; PDA—patent ductus arteriosus; PV/PS - pulmonary stenosis; TGA - transposition of great vessels; TOF—tetralogy of Fallot; VSD - ventricular septal defect Gene mutations usually cause the simultaneous development of heart defects and damage to other organs. Types of inheritance can be linked to the X chromosome, transmitted with dominant or recessive genes.
The impact of environmental factors on a pregnant woman is most dangerous in the 1st trimester, because at this time the formation of fetal organs occurs. Congenital heart defects are caused by:
The rubella virus causes visual impairment due to glaucoma, cataracts, underdevelopment of the brain, abnormalities in the skeletal structure, hearing loss, as well as pathologies such as defects in the septum of the heart, incorrect position of large vessels. After birth, the ductus arteriosus remains open, and the aorta and pulmonary artery can unite into a joint trunk.
A pregnant woman's intake of alcoholic beverages, amphetamine, anticonvulsants, lithium salts and progesterone, which is prescribed to maintain pregnancy, can contribute to narrowing of the pulmonary artery, aorta, valve defects, or interventricular septum.
Diabetes mellitus and a prediabetic condition in the mother lead to abnormal position of blood vessels and lack of integrity of the heart septa. If a pregnant woman suffers rheumatoid arthritis or , then the likelihood of the child developing a heart defect increases.
Children are more likely to suffer from defects if:
- expectant mother under 15, over 40 years old;
- the first trimester of pregnancy was with severe toxicosis;
- there was a possibility of miscarriage;
- there were deviations in the functioning of endocrine organs;
- close relatives suffered from cardiac development disorders since childhood.
Mechanism of development of functional disorders
Under the influence of risk factors, disturbances in the structure of the chromosomal apparatus in the fetus, the partitions between the chambers of the heart do not close in a timely manner, valves are formed of an irregular anatomical shape, the primary tube of the heart does not rotate enough, and the vessels change their location.
Normally, after childbirth, in children, the oval foramen between the atria and the ductus arteriosus close, since their functioning is necessary only for the period intrauterine development. But some children with congenital anomalies they remain open. When the fetus is in the uterus, its blood circulation does not suffer, but after childbirth or later, abnormalities in the functioning of the heart appear.
The timing of the occurrence of disorders depends on the time of healing of the hole connecting the systemic and pulmonary circulation, the degree of hypertension in the pulmonary system, as well as general condition baby, the possibility of developing adaptive reactions.
The development of so-called pale defects is associated with the discharge of blood from the systemic to the pulmonary circulation, and pulmonary hypertension occurs. Without surgery, only half of children survive to 1 year. The high probability of mortality in such newborns is associated with an increase in circulatory failure.
If the child has outgrown the dangerous age, then the outflow of blood into pulmonary vessels decreases, the state of health improves until sclerotic changes and an increase in pressure in the circulatory system of the lungs appear.
Venous-arterial discharge leads to the appearance of “blue” defects; they cause a decrease in the oxygen content in the blood. The formation of circulatory disorders goes through a number of stages:
1. Destabilization of the condition due to infectious and other concomitant diseases.
2. The systemic circulation is overloaded, and there is not enough blood in the pulmonary circulation.
3. Collateral vessels develop - the state of health stabilizes.
4. With prolonged overload, the heart muscle weakens.
6. Heart failure progresses.
Surgical treatment is indicated for defects accompanied by bluish skin color, if possible in the earliest period.
Classification of congenital heart valve defects
The clinical picture of heart defects makes it possible to distinguish three types: “blue”, “pale”, obstruction of blood exiting the ventricles.
Defects with cyanotic skin color include Fallot's disease and disorders of the position of the great vessels, fused tricuspid valve. With “pale” defects, blood is discharged from the arterial into the venous bed - an unclosed ductus arteriosus, anomalies in the structure of the septum of the heart. The difficulty of blood passing from the ventricles is associated with narrowing of blood vessels - stenosis, narrow pulmonary artery.
To classify congenital heart defects, the principle of impaired blood supply to the lungs can be chosen. With this approach, the following groups of pathologies can be distinguished:
- pulmonary circulation is not impaired;
- large blood flow to the lungs;
- poor blood supply to the lungs;
- combined defects.
Structure of congenital heart disease depending on the type of hemodynamic disorder Pulmonary blood flow is close to normal
Such defects include narrowing of the aorta, absence or fusion of its valve, and pulmonary valve insufficiency. A septum may appear in the left atrium, dividing it into two parts - a type of pathology is formed. The mitral valve may become deformed, close loosely, or narrow.
Increased blood volume in the lungs
“White” defects may occur: defects in the septa, fistula between large vessels, Lutambashe’s disease. Skin cyanosis develops with a large hole in the interventricular septum and fusion of the tricuspid valve, with an unclosed ductus arteriosus with high pressure in the pulmonary circulatory system.
Low blood supply to the lungs
Without cyanosis, there is a narrowing of the artery supplying the lungs with blood. Complex pathologies of the structure of the heart - Fallot's defects, and a decrease in the right ventricle are accompanied by a bluish color of the skin.
Combined defects
These include disturbances in communication between the chambers of the heart and the great vessels: Taussig-Bing pathology, abnormal origin of the aorta or pulmonary artery from the ventricle; instead of two vascular trunks there is one common one.
Signs of heart defects in a child
Cyanosis of the nasolabial triangle The severity of symptoms depends on the type of pathology, the mechanism of circulatory disorders and the time of manifestation of cardiac decompensation.
The clinical picture may include the following signs:
- cyanotic or pale mucous membranes and skin;
- the child becomes restless and quickly weakens when feeding;
- shortness of breath, rapid heartbeat, irregular rhythm;
- with physical stress, symptoms intensify;
- retarded growth and development, slow weight gain;
- There are heart murmurs when listening.
With the progression of hemodynamic disorders, edema, an increase in heart size, hepatomegaly, and emaciation appear. The addition of an infection can cause pneumonia and endocarditis. A characteristic complication is thrombosis of the blood vessels of the brain, heart, and peripheral vascular bed. Attacks of shortness of breath and cyanosis, fainting occur.
About the symptoms, diagnosis and treatment of congenital heart disease in children, watch this video:
Diagnosis of congenital heart disease
The examination data helps to assess skin color, the presence of pallor, cyanosis; auscultation reveals weakening, splitting or strengthening of tones.
Instrumental examination for suspected congenital heart defect includes:
- X-ray diagnostics of the chest organs;
- echological examination;
- phono-CG;
- angio-CG;
- cardiac probing.
ECG - signs: hypertrophy of various parts, conduction anomalies, disturbed rhythm. With the help of daily monitoring, hidden arrhythmias are detected. Phonocardiography confirms the presence of pathological heart sounds and noise.
According to X-ray examine the pulmonary pattern, location of the heart, outline and size.
Echological research helps determine anatomical deviations of the valve apparatus, septa, position of large vessels, and motor ability of the myocardium.
Treatment options for congenital heart defects
The choice of treatment method is determined by the severity of the child’s condition – the degree of heart failure, cyanosis. In a newborn child, surgery can be postponed if these signs are mild, and constant monitoring by a cardiac surgeon and pediatrician is required.
Treatment of congenital heart disease
Drug therapy includes the use of drugs that compensate for heart failure: vasodilators and diuretics, cardiac glycosides, antiarrhythmic drugs.
Antibiotics and anticoagulants may be prescribed if indicated or to prevent complications (with concomitant diseases).
Surgical intervention
The operation is prescribed in case of oxygen deficiency to temporarily alleviate the child’s condition. In such situations, various anastomoses (connections) are applied between the main vessels. This type of treatment is definitive for combined or complex disorders of the heart structure, when radical treatment is not feasible. In severe situations, a heart transplant is indicated.
Under favorable circumstances, after palliative surgical treatment has been performed, plastic surgery, suturing of cardiac septa, and intravascular blockage of the defect are performed. In the case of pathology of the great vessels, removal of a part, balloon expansion of the narrowed area, plastic restoration of the valve or stenosis are used.
Prognosis for congenital heart defects
The most common cause of death in newborns is heart defects. Before one year of age, 50 to 78 percent of children die without specialized care in a cardiac surgery department. Since the possibilities of performing operations have increased with the advent of more advanced equipment, the indications for surgical treatment are expanding, they are performed at an earlier age.
After the second year, compensation for hemodynamic disorders occurs, and child mortality decreases. But since signs of weakness of the heart muscle gradually progress, the need for surgery cannot be ruled out in most cases.
Preventive measures for those planning pregnancy
Women at risk of developing heart defects in a child should undergo a consultation at a medical genetic center before planning a pregnancy.
This is required if you have illnesses endocrine system, and especially with diabetes mellitus or a predisposition to it, rheumatic and autoimmune diseases, the presence of patients with developmental defects among close relatives.
In the first three months, a pregnant woman should avoid contact with patients with viral and bacterial infections. infectious diseases, taking medications without a doctor’s recommendation, completely abstain from drinking alcohol, drugs, and smoking (including passive smoking).
If a possible heart defect is suspected in the fetus, an ultrasound examination, amniotic fluid analysis, and chorionic tissue biopsy are performed. If deviations from the norm are detected, the question of terminating the pregnancy is raised.
Unfortunately, congenital heart disease is not uncommon. However, with the development of medicine, even this problem can be solved, which will increase the child’s chances of a happy and long life.
For tips for parents whose children have congenital heart defects, watch this video:
Read also
Treatment in the form of surgery may be the only chance for patients with atrial septal defect. It can be a congenital defect in a newborn, manifest in children and adults, or secondary. Sometimes it closes on its own.
Congenital heart defects are one of the most common developmental anomalies, ranking third after anomalies of the central nervous system and musculoskeletal system. The birth rate of children with congenital heart defects in all countries of the world, including Russia, ranges from 2.4 to 14.2 per 1000 births.
Problems of diagnosis and treatment of congenital heart defects are extremely important in pediatric cardiology. General practitioners and cardiologists, as a rule, are not sufficiently familiar with this pathology due to the fact that the vast majority of children by the age of puberty have already received surgical treatment or died.
The causes of congenital heart defects are unclear. Heart defects occur at 3-7 weeks of pregnancy, during the formation and formation of heart structures. In the first trimester of pregnancy (4-8-12 weeks), under the influence of various teratogenic influences, the formation of the anatomical structures of the cardiovascular system is disrupted, resulting in the formation of defects in the septum of the heart, narrowing of the cardiac ostia, changes in the shape of the valves, etc. .
Congenital heart defects traditionally include fetal communications that have not closed as a result of disruption of postnatal hemodynamic restructuring (in particular, a patent ductus arteriosus).
Relevance
Significant prevalence of congenital heart disease in the pediatric population. In Russia, up to 35,000 children with congenital heart disease are born annually, which is 8-10 per 1,000 children born alive. In Yaroslavl and the region, the statistics on the prevalence of congenital heart disease coincides with the all-Russian one. The incidence of congenital heart disease among children aged 0 to 14 years is 8.11‰, among adolescents - 5.4‰ (based on the results of 2009). CHD accounts for 22% of all congenital malformations.
There is an increasing trend in the prevalence of congenital heart defects.
This is facilitated by:
Increase in hereditary and infectious pathologies.
Deterioration of the environmental situation,
- “aging” of pregnant women, deterioration of their health, “ bad habits" and etc.
Along with this, the number of more complex and severe heart defects is increasing.
High mortality rate with congenital heart disease:
- According to T.V. Pariyskaya and V.I. Gikavogo (1989) in St. Petersburg, the mortality rate of patients with congenital heart disease during the first year of life is 40%, of which among newborns - 48.3%, among children 1-3 months - 32.4%, 4-8 months - 19, 3%.
- After the first year of life, mortality from congenital heart disease decreases and among children aged 1 to 15 years it is 5% of total number patients born with congenital heart disease (N.A. Belokon, V.I. Podzolkov, 1991).
Therefore, congenital heart diseases occupy one of the leading places in the structure of causes of infant mortality (2-3rd place) and childhood disability. Among congenital malformations leading to disability, congenital defects account for about 50% (E.F. Lukushkina, 2000; L.I. Menshikova, T.T. Kuzmina, 2003).
Etiology of congenital heart defects
Mutations
Exogenous and endogenous environmental factors
Multifactorial inheritance
CHD caused by genetic disorders can occur both in isolation and as part of syndromes with multiple congenital malformations - MCPD:
Down syndrome (trisomy 21),
Patau syndrome (trisomy 13),
Edwards syndrome (trisomy 18),
Shereshevsky-Turner syndrome (X0).
Polygenic-multifactorial inheritance is the cause of congenital heart disease in 90% of cases.
Influence of external factors:
- Infectious agents (rubella virus, cytomegalovirus, herpes simplex virus, influenza virus, enterovirus, Coxsackie B virus, etc.).
- Somatic diseases of the mother, primarily diabetes mellitus, lead to the development of hypertrophic cardiomyopathy and congenital heart disease.
- Occupational hazards and bad habits of the mother ( chronic alcoholism, computer radiation, intoxication with mercury, lead, exposure to ionizing radiation, etc.).
- Environmental problems.
- Socio-economic factors.
- Psycho-emotional stressful situations.
Risk factors for having children with congenital heart disease:
Mother's age;
Endocrine diseases of spouses;
Toxicosis and threat of termination of the first trimester of pregnancy;
History of stillbirths;
Presence of children with congenital heart disease in close relatives.
Only a geneticist can quantitatively assess the risk of having a child with congenital heart disease in a family, but every doctor can and should give a preliminary prognosis and refer parents for medical and biological consultation.
Classification of congenital heart defects (Marder, 1953)
|
Hemodynamic group of congenital heart disease |
Without cyanosis |
With cyanosis |
|
With hypervolemia of the pulmonary circulation |
PDA, ASD, VSD, AVK, CHADLV, Lutembashe complex, |
TMA without pulmonary stenosis, OSA, total APPV, double outlet of vessels from the right ventricle. Set Eisenmenger, left heart (hypoplasia of the left heart) |
|
With hypovolemia of the pulmonary circulation |
Fallot's defects, TMA with pulmonary artery stenosis, tricuspid valve atresia, Ebstein's anomaly, rightness (hypoplasia of the right heart) |
|
|
With hypovolemia of the systemic circulation |
Aortic stenosis, aortic coarctation, aortic arch interruption |
|
|
Without hemodynamic disturbances in the systemic and pulmonary circulation |
Abnormalities of cardiac position, MARS, double aortic arch, anomalies in the origin of blood vessels from the aortic arch |
Working group of the 9 most common CHDs (N.A. Belokon, V.P. Podzolkov, 1991)
1. Congenital heart defects of the pale type with arteriovenous shunting of blood:
- ventricular septal defect (VSD),
- atrial septal defect (ASD),
- patent ductus arteriosus (PDA).
2. Congenital heart defects of the blue type with venous-arterial shunting of blood:
- tetralogy of Fallot,
- transposition of the great vessels,
- atresia of the tricuspid valve.
3. Congenital heart defects of the pale type without blood discharge, but with an obstruction to the flow of blood from the ventricles:
Pulmonary artery stenosis,
Coarctation of the aorta.
Phases of the natural history of congenital heart disease
I. Adaptation phase.
The duration of the adaptation phase is from several weeks to 2 years.
Due to the peculiarities of intrauterine hemodynamics (the presence of the placental circulation and fetal communications), the fetus with most congenital heart diseases does not develop decompensation.
With the birth of a child the cardiovascular system the newborn adapts to extrauterine hemodynamic conditions: the circulatory circles are disconnected, both general and intracardiac hemodynamics are established, the pulmonary circulation begins to function, followed by a gradual closure of fetal communications: the ductus arteriosus and the oval window.
Under these conditions, with compensation mechanisms still undeveloped, hemodynamics often turn out to be inadequate, and various complications develop. The child’s condition is progressively and sharply deteriorating, which forces conservative therapy and emergency surgical interventions.
Complications of the adaptation phase of congenital heart disease
In patients with congenital heart disease of the first and third hemodynamic groups:
Circulatory failure (early, emergency)
Hypostatic pneumonia
Early pulmonary hypertension
Dystrophy (hypotrophy)
Rhythm and conduction disorders
Dyspnea-cyanotic (hypoxemic) crises.
Cerebrovascular accident.
Relative anemia
With any congenital heart disease there is a high risk of developing bacterial endocarditis.
2. Phase of relative compensation (phase of imaginary well-being). Lasts from several months to tens of years.
This period is characterized by connection large quantity compensatory mechanisms in order to ensure the existence of the body in conditions of impaired hemodynamics.
There are cardiac and extracardiac compensatory mechanisms.
Cardiac include:
Increased activity of enzymes of the aerobic oxidation cycle (succinate dehydrogenase);
The entry into action of anaerobic metabolism;
Frank-Starling Law;
Hypertrophy of cardiomyocytes.
Extracardiac compensation mechanisms include:
- activation of the sympathetic part of the ANS, which leads to an increase in the number of heart contractions and centralization of blood circulation;
- increased activity of the renin-angiotensin-aldosterone system, as a result of which it increases arterial pressure and maintains adequate blood supply to vital important organs, and fluid retention leads to an increase in the volume of circulating blood.
At the same time, the retention of excess fluid in the body and the formation of edema is resisted atrial natriuretic factor;
- erythropoietin stimulation leads to an increase in the number of red blood cells and hemoglobin and, thus, an increase in the oxygen capacity of the blood.
Complications of the relative compensation phase
- Bacterial endocarditis.
- Relative anemia.
3. Decompensation phase (terminal phase).
This period is characterized by the depletion of compensatory mechanisms and the development of heart failure refractory to treatment; the formation of irreversible changes in internal organs.
Complications of the decompensation phase of congenital heart disease (terminal phase)
In patients with congenital heart disease first and third
hemodynamic groups:
- Chronic circulatory failure.
- Pulmonary hypertension.
- Dystrophy.
- Rhythm and conduction disorders.
In patients with cyanotic congenital heart disease:
- Dyspnea-cyanotic (hypoxemic)
- Cerebrovascular accident.
- Relative anemia.
- Hypoxic hemorrhagic vasculitis.
- Hepatorenal syndrome.
- Hypoxic arthritis.
In patients with aortic defects:
- Arterial hypertension.
- Angina syndrome.
With all congenital heart disease, the risk of developing bacterial endocarditis remains
Prenatal diagnosis and prenatal assessment of the severity of congenital heart disease
For some children with congenital heart disease, emergency surgical interventions must be performed in the first hours after birth to save life. Therefore, prenatal diagnosis and prenatal assessment of the severity of congenital heart disease is sometimes crucial for providing the child with timely specialized (including cardiac surgical) care.
Prenatal diagnosis of the fetus using ultrasound examination(ultrasound) is currently performed routinely for all pregnant women at 10-12, 20-22 and 32-34 weeks of pregnancy. Among the large list of tasks of this study is the diagnosis of developmental defects, including malformations of the cardiovascular system.
Prenatally detected congenital heart defects are divided into 5 categories according to severity and risk of poor prognosis
Heart defects of the first and second categories, in particular, transposition of the great arteries (TMA), double origin of vessels from the right ventricle, truncus arteriosus, extreme degree of tetralogy of Fallot, pulmonary atresia with valvular agenesis, interruption of the aortic arch, etc. often create critical life-threatening conditions situations in the neonatal period and infancy. Children with these heart defects should be seen by a cardiologist and cardiac surgeon immediately after birth.
In Moscow on the basis of Gorodskaya clinical hospital No. 67, a specialized department has been created where women pregnant with a fetus with a “critical” variant of congenital heart disease are hospitalized for delivery. If necessary, the newborn baby is immediately transported for surgical treatment to Science Center Cardiovascular Surgery named after. Bakuleva.
For some heart defects of the first group and at the current level of development of cardiac surgery, it is impossible to perform full-fledged surgical correction. They are accompanied by high natural and postoperative mortality. If such defects are detected prenatally, then the question of terminating the pregnancy arises (!?).
Early postnatal diagnosis of congenital heart disease
Clinical symptoms that are alarming for congenital heart disease in newborns:
(neonatologist of the maternity hospital and neonatal pathology departments)
1. Central cyanosis from birth or after some time, which is not eliminated by the administration of oxygen.
2. A murmur over the heart area may be a sign of a defect, but the child may also have physiological murmurs and murmurs associated with the persistence of fetal communications. In addition, the most severe heart defects are often not accompanied by a murmur.
3. Persistent tachycardia or bradycardia not associated with neurological pathology or somatic condition.
4. Tachypnea more than 60 per minute, including during sleep, with or without retraction of the compliant areas of the chest.
5. Symptoms of circulatory failure (including hepatomegaly, edema, oliguria).
6. Irregular heart rhythm.
7. Reduction or absence of pulsation on lower limbs(KA);
8. Generalized weakening of the pulse - suspicion of hypoplasia of the left heart or circulatory shock.
9. “High” pulse - suspicion of blood discharge from the aorta with low diastolic blood pressure (PDA, OSA).
Additional examinations for suspected congenital heart disease in the neonatal period:
- Hyperoxic test - positive with cyanosis central genesis. In congenital heart disease with right-to-left blood shunting, general early cyanosis is of central origin and is caused by the discharge of venous blood into big circle blood circulation and a decrease in the partial oxygen content in arterial blood. A newborn child with severe general cyanosis is inhaled with 100% oxygen through a mask for 10 to 15 minutes under the control of a blood gas analysis. With congenital heart disease, cyanosis does not decrease or decreases slightly. The test results should be considered in conjunction with other diagnostic signs.
- ECG, echocardiography, x-ray of the chest organs in 3 projections (frontal, right and left anterior oblique).
- Measurement of blood pressure in the brachial and femoral arteries.
Criteria for diagnosing CHD in infancy and early age (local pediatrician, doctor general practice, pediatric cardiologist)
- Clinical data: cyanosis, shortness of breath, retardation in physical development, symptoms of heart failure, cardiac hump, cardiomegaly, changes in heart sounds and rhythm, organic murmurs, changes in blood pressure.
- Electrocardiography: position el. cardiac axis, myocardial hypertrophy, dysmetabolic changes in the myocardium.
- ECHOKgr.
- Changes on a chest x-ray.
- Arterial hypoxemia (as measured by blood gases)
