What is Tetralogy of Fallot? Tetralogy of fallot in newborns Notebook of fallot.

Tetralogy of Fallot is one of the types of congenital heart defects.

It is characterized by four signs: dextraposition (incorrect right-sided position) of the aorta, the presence of a gap in the wall located between the two ventricles, significant dilation of the right ventricle and stenosis of its outlet section.

This form of the defect is closest to the triad and pentade of Fallot, which have, respectively, 3 (there is no displacement of the aorta) and 5 characteristic signs (including pathology of the interatrial septum), the same as those that characterize tetralogy of Fallot.

This pathology accounts for about 10% of all cases of congenital heart defects. If we talk about congenital heart disease of the cyanotic type, it occurs in half of the cases.

With such a violation, the conus arteriosus changes its location, and the aortic valve moves to the right of the pulmonary valve. It appears above the septum located between the two ventricles, while there is no attachment of the wall of the arterial cone to the septum itself: this occurs because a defect occurs in it.

The pulmonary trunk becomes narrowed and lengthens, and the right ventricle enlarges, due to the fact that it is difficult for blood to enter the artery leading to the lungs.

The presence of an opening between the ventricles facilitates the mixing of blood entering the aorta. Mixed blood, in turn, has a low oxygen content.

How does hemodynamics change?

Most often, with this disease, the mouth located in the artery is blocked. In this case, additional branches of vessels appear that supply the lungs with arterial blood. After which it mixes, and venous blood is discharged into the left ventricle - the “white” form changes to “blue”.

Tetralogy of Fallot is of the “blue” type because the mixing of arterial and venous blood leads to cyanosis.

In general, the movement of blood through the vessels is determined by how severe the artery stenosis is. It also correlates with how clearly arterial hypoxemia manifests itself, as well as the severity of the condition of the body as a whole. If the stenosis is significant, then blood flows from the ventricles into the aorta, but its flow into the pulmonary artery is difficult.

The volume in which the systemic circulation is expressed is increased. Moreover, since the aorta is located in the shape of a “rider”, blood flows freely into it from the right ventricle, and insufficiency does not develop in it, and the pressure in the ventricles is equalized.

The extreme form of the disease involves the entry of arterial blood into the pulmonary circulation through collaterals or open arterial flow. The moderate form has the following features: the release of blood into the aorta is higher than into the lungs, a left-right discharge occurs, which is why the clinical manifestation has a pale form of the defect.

The moderate form of tetralogy of Fallot most often occurs in young children, but there are also cases of manifestation in adolescents.

Development factors

The most common factor due to which Fallot's disease occurs and develops is a disorder that occurs in the development of the heart during the period from the second to the eighth week of embryonic growth, when the formation of this organ occurs.

In addition, the disease can occur due to the fact that during pregnancy the woman suffered from infectious diseases, for example, measles.

The intake of alcohol, drugs and medications in the presence of contraindications for pregnancy also has a negative effect.

Sometimes this heart defect can occur unexpectedly, for no apparent reason. The processes that can lead to these consequences have not yet been sufficiently studied.

The influence of heredity on the possibility of a child developing a defect is also noted.

Possible types of pathology

There are several options for the development of the disease.

Anatomical signs can appear either together or one at a time:

With tetralogy of Fallot, the following forms of hemodynamic disturbances occur, which were identified in the clinical and anatomical classification:

• cyanotic in combination with stenosis of the orifice;
• acyanotic.

Sometimes a third form is also distinguished: in this case, there is atresia of the mouth of the pulmonary artery.

Fallot's defect can also have a severe, classic and mild form:

• In the first case, shortness of breath and cyanosis occurs in infants during feeding from birth.
• In the second, the first manifestations of the disease occur in a child aged from six months to a year.
• In the third - from 6 years of age until puberty.

Characteristic symptoms

The manifestations of this disease vary depending on what stage of development it is at, there are three in total:

According to the timing, the first manifestations begin to appear from birth and can either completely disappear or remain until the end of life.

Diagnostic methods

When diagnosing, the following clinical picture is usually distinguished:

• the patient experiences frequent fainting;
• he cannot take a deep breath;
• dextroposition of the aorta and myocardial hypertrophy are detected;
• Pain in the thoracic region periodically appears.

When identifying a disease such as tetralogy of Fallot, the most effective diagnosis is considered to be an intrauterine examination.

It is carried out using an ultrasound machine, the accuracy of the result depends on its level. If the fetus is examined by a specialist on time, then it is possible to detect the disease at an early stage: up to 21 weeks.

In the third trimester, the probability of detecting such a disorder is about 100%. In severe cases of the defect, differential diagnosis is carried out to help determine an accurate diagnosis: a number of obvious signs of the disease present in a newborn do not always indicate that it is tetralogy of Fallot.

In addition to carrying out, the defect can be identified using genetic research. Such screening is mandatory for a period of about 4 months. Moreover, in 35% of pathology detections, it can be combined with diseases resulting from chromosome disorders, for example, Down syndrome.

When diagnosing Fallot's defect, echocardiography is also performed, which helps to make the most accurate diagnosis, especially if it is in infants. The echocardiogram result determines the subsequent treatment strategy.

Color Doppler ultrasound, in turn, determines the direction of blood flow.

Auscultation helps to listen to systolic murmurs located in the left edge of the chest. The apex beat of the heart is usually weak and can be palpated in the 4th-5th intercostal space. And also by auscultation it is possible to determine the transmitting pulsation located in the epigastric region.

An x-ray is also one of the important components of a comprehensive analysis, since x-rays can reveal signs of a specific form of the disease. In this way, important radiological signs can be determined: displacement of the aorta, location of the septum conus and the condition of other organs.

How is the treatment carried out?

The choice of the most effective treatment depends on the specific type of Fallot's disease.

In this case, the use of glycosides is contraindicated for the patient, as they can provoke an attack. Radical correction using surgical methods, in turn, is most often carried out in case of a multicomponent type of disease or complications.

Help during a seizure

With this diagnosis, patients at the cyanotic stage can sometimes develop heart failure. This happens due to frequent dyspnea-cyanotic attacks.

If an attack occurs, proceed as follows:

• lay the patient on his side, bend his legs to his stomach or squat;
• provide oxygen;
• give an injection or drip with morphine;
• if no improvement is observed, an injection of sodium bicarbonate is given;
• for convulsions, hydroxybutyrate is administered.

The dosage of medications should be prescribed by the doctor who is seeing the patient.

Surgery

In most cases, radical correction is chosen as treatment, otherwise the prognosis is quite disappointing: without treatment, the disease in severe form is fatal for children under the age of one year.

In pediatrics, the disease itself is an indication for surgery, unless the child has a contraindication in the form of pulmonary hypertension or other exceptional factors.

Surgical intervention occurs as follows:

• first close the hole in the septum;
• then, depending on the severity of the disease, part/all of the heart muscle on the right side is removed, the valve is adjusted/replaced, or a shunt is installed between the heart and the vessels connecting to the lungs.

In 80% of cases, surgical interventions for this pathology are successful. There are also cases when it is necessary to carry out not one, but several operations. After this, the patient should undergo regular follow-up.

The price of a particular operation depends on its complexity and whether subsequent intervention will be necessary. On average in Moscow, its cost varies from 132,000 to 200,000 rubles.

Forecast for future life

On average, life expectancy with such a diagnosis in a mild form is up to 12 years, if the patient does not undergo surgery, regardless of when the diagnosis was made.

And only 5% of people with a mild form of the defect, who had it in childhood, but were not operated on, survive to the age of 40 years. An adult who underwent surgery as a child should be constantly monitored by specialists and take maintenance medications.

Even during surgery, there is a possibility of a sudden stroke, which threatens the patient’s life and in some cases can be fatal.

Specialists who studied pathology identified the following pattern: the earlier the surgical intervention was performed, the greater the likelihood of a positive outcome.

Children belonging to the blue type have tetralogy of Fallot. This anomaly becomes a frequent cause of death of a child in infancy or significantly shortens his life. On average, children with unoperated tetralogy of Fallot survive only up to 12-15 years, and less than 5% of patients survive until the age of 40. With such a heart defect, the child may lag behind in physical or mental development. And the cause of death of such patients is ischemic stroke, provoked by vascular thrombosis, or brain abscess.

Tetralogy of Fallot is a complex congenital heart defect and is accompanied by the following four characteristic morphological signs: extensive ventricular septal defect, stenosis (narrowing of the lumen) of the outflow tract of the right ventricle, unnatural location of the aorta and myocardial hypertrophy of the walls of the right ventricle. This anomaly of cardiac development received its name from the French pathologist E.L.A. Fallot, who first described its anatomical and morphological characteristics in detail in 1888.

The severity and nature of the symptoms of tetralogy of Fallot depends on many morphological features present in each specific clinical case, and the severity of such a defect is determined by the measure of stenosis of the outflow tract of the right ventricle, the mouth of the pulmonary artery and the size of the defect in the septum of the cardiac ventricles. The greater the degree of these anatomical anomalies, the more severe the clinical manifestations and course of the defect.

Cardiac surgery is indicated for all children with tetralogy of Fallot, which in many cases may consist of more than one operation. As a rule, one of these interventions is palliative, and the second involves radical surgical correction of the existing anomalies.

In this article, we will introduce you to the presumed causes, forms, symptoms, methods of diagnosis and surgical correction of tetralogy of Fallot in children. This information will help you understand the danger and essence of this anomaly, and you can ask your doctor any questions you have.

Some viral infections suffered by a pregnant woman mainly in the first trimester can cause the development of congenital heart disease in the fetus

Anatomical abnormalities in the structure of the heart are formed in the fetus at 2-8 weeks of embryogenesis. The reasons for changes in normal cardiogenesis can be factors affecting the body of a pregnant woman, which cause the development of other congenital defects:

• taking certain medications;
• heredity;
• past infections;
• bad habits;
• work in hazardous industries;
• unfavorable environment;
• severe chronic diseases.

Tetralogy of Fallot often accompanies such a congenital pathology as Amsterdam dwarfism syndrome.

The formation of the tetralogy of Fallot occurs as follows:

• due to improper rotation of the conus arteriosus, the aortic valve moves to the right of the pulmonary valve;
• the aorta is located above the septum of the cardiac ventricles;
• due to the “rider aorta,” the pulmonary trunk shifts and becomes more elongated and narrowed;
• due to the rotation of the conus arteriosus, its septum does not connect with the ventricular septum and a defect is formed in it, which subsequently leads to the expansion of this chamber of the heart.

Varieties

Depending on the nature of the stenosis of the right ventricular outflow tract, four types of tetralogy of Fallot are distinguished:

• embryological - obstruction is caused by an incorrect location of the conical septum downwards and/or forward and to the left, the fibrous ring of the pulmonary valve is almost unchanged or is moderately hypoplastic, and the area of ​​maximum narrowing coincides with the level of the demarcating muscular ring;
• hypertrophic - obstruction is caused not only by displacement of the conical septum downward and/or forward and to the left, but also by pronounced hypotrophy of its proximal part, and the area of ​​maximum narrowing coincides with the level of the demarcating muscle ring and the opening of the outflow tract of the right ventricle;
• tubular - obstruction is provoked by an uneven distribution of the common arterial trunk and because of this, the pulmonary cone is shortened, narrowed and hypoplastic (with this type of defect, pulmonary valve stenosis and hypoplasia of the fibrous ring may be present);
• multicomponent - obstruction is caused by a high departure of the septal-marginal trabecula of the moderator cord or excessive elongation of the conical septum.

Depending on the characteristics of circulatory disorders, tetralogy of Fallot can occur in the following forms:

• with atresia (abnormal overlap) of the pulmonary artery;
• with cyanosis and varying degrees of narrowing of the pulmonary artery mouth;
• without cyanosis.

Hemodynamic disorders

Blood circulation in tetralogy of Fallot is altered due to stenosis of the right ventricular outflow tract and the absence of part of the septum between the ventricles. The severity of such violations is determined by the size of the defects.

With significant narrowing of the pulmonary artery and a large size of the ventricular septal defect, a smaller amount of blood enters the pulmonary bed, and a larger amount enters the aorta. This process causes insufficient enrichment of arterial blood with oxygen and manifests itself. A large septal defect causes a comparison of pressure levels in both cardiac ventricles, and when the mouth of the pulmonary artery is completely blocked from the aorta, blood enters the pulmonary circulation through the ductus arteriosus or other bypass routes.

With moderate narrowing of the pulmonary artery, blood discharge due to high peripheral resistance occurs from left to right and cyanosis does not appear. However, over time, due to the progression of stenosis, the blood discharge becomes cross, and then right-left. As a result, the patient develops cyanosis.

Symptoms

Before birth, tetralogy of Fallot does not manifest itself in any way, and in the future the severity of its symptoms will depend on the size and nature of the anatomical abnormalities.

The main first sign of tetralogy of Fallot is cyanosis, and depending on the time of its occurrence, five clinical forms of this heart defect are distinguished:

• early cyanotic – cyanosis appears in the first two to three months of a child’s life;
• classic - cyanosis first appears at 2-3 years of age;
• severe – the defect is accompanied by the occurrence of cyanotic crises;
• late cyanotic - cyanosis first appears at 6-10 years of age;
• acyanotic - cyanosis does not appear.

In severe forms of the defect, cyanosis first appears at 2-3 months and is maximally manifested by the first year of the child’s life. Blue skin and shortness of breath occur after any physical activity: feeding, changing clothes, crying, overheating, straining, active play, walking, etc. The child feels weak, dizzy and the pulse quickens. When starting to walk, to alleviate this condition, such children often squat down, since in this position their well-being improves.

In severe forms of the defect, cyanotic crises may appear in the child by the age of 2-5 years. They develop suddenly and are manifested by the following symptoms:

• general anxiety;
• increased manifestations of cyanosis;
• severe weakness;
• increased heart rate;
• loss of consciousness.

Over time, such crises appear more and more often. In severe cases, such attacks can end with the onset of hypoxic coma, respiratory arrest and the appearance of convulsions.

Children with tetralogy of Fallot often suffer from acute respiratory viral infections, various inflammatory diseases of the upper respiratory tract and pneumonia. They are often adynamic and retarded in development, and the degree of such deviations depends on the severity of cyanosis.

At an older age, children experience deformation of the fingers and nail plates of the “drumstick” and “watch glass” type.

With the acyanotic form of tetralogy of Fallot, children usually rarely squat, develop well and experience early childhood without problems. After this, they undergo radical cardiac surgery as planned (usually at the age of 5-8 years).

When examining a child with tetralogy of Fallot and listening to heart sounds, the following are revealed:

• heart hump (not always);
• rough systolic murmur to the left of the sternum in the II-III intercostal space;
• weakened II tone in the projection of the pulmonary artery.

Diagnostics

A doctor can suspect the presence of tetralogy of Fallot in a child by the bluish color of the skin, a tendency to squat, and characteristic heart murmurs.

To clarify the diagnosis and obtain a complete clinical picture of this congenital anomaly, the following types of studies are prescribed:

• chest x-ray – moderate increase in heart size, unclear pulmonary pattern, shoe-shaped heart;
• – deviation of the electrical axis of the heart to the right, signs of right ventricular myocardial hypertrophy, incomplete;
• phonocardiography – a typical picture of murmurs and changes in heart sounds;
• – pulmonary artery stenosis, ventricular septal defect, atypical location of the aorta, right ventricular myocardial hypertrophy;
• – increased pressure in the right ventricle, communication between the ventricles through an existing defect, low oxygenation of arterial blood;
• pulmonary arteriography and aortography – the presence of collateral blood flow, pulmonary artery stenosis, patent ductus arteriosus.

If necessary, the examination of the child can be supplemented with MRI and MSCT of the heart, selective and ventriculography.

Treatment

All children with tetralogy of Fallot are indicated for surgical correction of the defect. The method of cardiac surgery and the timing of its implementation depend on the anatomical variant of the anomaly, the severity of its manifestations and the age of the patient.

Before surgery, children are recommended to undergo gentle treatment and drug therapy aimed at relieving cyanotic crises. For this purpose, intravenous infusions of solutions of Eufillin, Reopoliglucin, Glucose and Sodium Bicarbonate are prescribed. To compensate for the lack of oxygen, oxygen therapy is performed.

If drug correction is ineffective, emergency surgery to apply an aortopulmonary shunt is indicated. Such palliative interventions of the anastomosing type include:

• intrapericardial anastomosis of the ascending aorta and the right pulmonary artery;
• Blalock-Taussig subclavian-pulmonary anastomosis;
• anastomosis between the descending aorta and the left pulmonary artery;
• imposition of a central aortopulmonary anastomosis with a prosthesis made of biological or synthetic material, etc.

To reduce the manifestations of arterial hypoxemia, the following operations can be performed:

• balloon valvuloplasty;
• open infundibuloplasty.

Radical corrective operations for tetralogy of Fallot are usually performed before the age of 6 months or up to 3 years, and for the anticyanotic form - at 5-8 years. In the process of such interventions, stenosis of the outflow tract of the right ventricle and a septal defect between the cardiac ventricles are eliminated.

With adequate cardiac surgical corrections, hemodynamics are stabilized and all symptoms of tetralogy of Fallot are eliminated. For six months after the operation, children are recommended to undergo clinical observation by a cardiac surgeon and cardiologist, refuse to attend kindergarten or school, take a gentle regimen with limited physical activity, antibiotic prophylaxis of endocarditis before dental and surgical procedures, and take medications prescribed by a doctor.

Over time, blood circulation in operated patients is completely stabilized, medications are stopped, but observation by a cardiologist remains relevant. Given the fact of the anatomical severity of tetralogy of Fallot and the difficulty of performing cardiac surgical correction, such children are recommended to always limit physical activity in the future. When choosing a profession, this factor must be taken into account.

Timely radical operations to correct tetralogy of Fallot usually give a good prognosis, and patients adapt well socially, become able to work and normally tolerate physical activity adequate for their condition. When such interventions are performed at a later age, long-term results worsen.

Tetralogy of Fallot is a dangerous and complex congenital heart defect, and when such an anomaly is detected, the child’s parents should always understand that only timely cardiac surgery can save the baby’s health and life. In severe forms, two operations have to be performed - palliative and radical corrective. After timely surgical treatment, the prognosis for survival becomes favorable, and children can lead a normal lifestyle, but with some limitation in physical activity.

Channel One, program “Live Healthy!” with Elena Malysheva, in the “About Medicine” section, a conversation about the tetralogy of Fallot (see from 32:35 min.):

Tetralogy of Fallot is one of the most severe congenital heart defects. The disease is accompanied by a high percentage of deaths. Moreover, the life expectancy of patients is very short - from fifteen to thirty years. This defect is treated with surgery, which is quite complex, due to the anatomical features of the pathology and the early age of the patient.

There are the following degrees of tetralogy of Fallot disease.

1. Bezcyanotic form. Typically, children with this degree of the disease develop satisfactorily. They tolerate the most difficult period well - early age. At five to eight years old, sick children are operated on.
2. Intermediate form. This is a more advanced degree of tetralogy of Fallot. At the age of three to seven years, palliative surgery is performed. In the future - radical surgical correction of the heart defect. If the situation allows, these operations can be carried out simultaneously.
3. Cyanotic form. This is the most severe degree of the disease, for which urgent surgical treatment is indicated. Correction of the defect is usually done in infancy.

Symptoms

Parents can notice symptoms of the disease quite early - from the fourth week of a newborn’s life. At first, the baby will develop chronic heart failure, shortness of breath and arrhythmia will appear, he will refuse the breast, and will become restless.

Tetralogy of Fallot also manifests itself in changes in the baby's appearance. And the severity of external symptoms will depend on the form of the disease and the extent of the septal defect.

So, the main symptoms of the disease.

1. Cyanosis. The baby's skin may turn blue while sucking and crying. As the disease progresses, blue discoloration will occur at rest. Moreover, first the nasolabial triangle, tips of the ears and fingers will turn blue, then general cyanosis may develop.
2. Weight loss.
3. Lag in physiological development. The child later begins to hold his head, sit up and crawl.
4. The appearance of flat feet.
5. Thickening of the fingertips and their resemblance to drumsticks.
6. The appearance of a wide distance between the teeth, the rapid development of dental diseases.
7. Thickening and rounding of nails.
8. The development of a “heart hump” is a thickening of the chest.

One of the characteristic signs of heart disease is a cyanostic attack, which is accompanied by:

• the appearance of shortness of breath in the baby;
• deepening breathing and increasing it up to eighty breaths per minute;
• sharp dilation of the pupils;
• the appearance of muscle tremors;
• blue-violet color of the skin;
• very severe weakness, in which hypoxic coma can develop.

Causes

The dangerous disease tetralogy of Fallot can appear in a newborn due to several reasons.

1. Heredity.
2. Violation of cardiogenesis in the embryo in the second to eighth weeks of development.
3. Infectious diseases suffered by a pregnant woman in the first trimester. For example, rubella, measles and scarlet fever.
4. The expectant mother's intake of medications (hormonal, sedatives and the like), narcotic drugs and alcoholic beverages.
5. Diabetes mellitus and hyperthyroidism in a pregnant woman.
6. Radiation and unfavorable environmental conditions in the place of residence.
7. Severe vitamin deficiency.
8. Prolonged fetal hypoxia.
9. Down syndrome.
10. Patau syndrome.

Sometimes tetralogy of Fallot occurs against the background of Cornelia de Lange syndrome. This is “Amsterdam dwarfism”, accompanied by mental defects and numerous external and internal developmental anomalies. For example, deformation of the ears, “clown face”, strabismus, astigmatism, syndactyly of the feet, lack of fingers, and so on.

Diagnostics

Translated from ancient Greek, “tetra” means “four”. This is exactly the number of heart defects that children with tetralogy of Fallot have.

The following pathologies are distinguished:

• enlargement of the right heart ventricle;
• dextroposition – displacement of the aorta to the right;
• pathology of the interventricular septum;
• reduction of the pulmonary artery.

What studies are performed by the doctor:

• electrocardiogram;
• cardiac catheterization or angiocardiography;
• ultrasound examination of the heart;
• blood analysis;
• X-ray.

The most informative for a specialist from the point of view of predicting the development of the disease are the degree of reduction of the pulmonary artery and the pathology of the interventricular septum. The process of blood circulation - hemodynamics - depends on them.

The more pronounced the reduction of the artery, the greater the load the right heart ventricle will receive. The large circle of the blood supply will be overfilled with venous blood, and the small circle will become deficient. This will lead to hypoxia of the child’s external and internal organs.

A blood test for Fallot group defects will show a sharp increase in hemoglobin. Reticulocytes will also appear in the blood, and platelet activity will decrease.

Treatment

Without exception, all patients diagnosed with tetralogy of Fallot require surgery. Only manifestations of a cyanotic attack can be treated with medication. This can be inhalation of moist air, intravenous injection of rheopolyglucin, sodium bicarbonate, aminophylline. If drug therapy does not help, an aortopulmonary anastomosis must be urgently performed.

The method of surgery for heart disease depends on the form of the disease, its anatomical features and the age of the patient. Palliative operations are indicated for newborns and children of an early age group. They help reduce the risk of postoperative complications during future radical surgery.

Radical correction is carried out for children aged from six months to three years. If done later, the results may be unsatisfactory, especially in patients over twenty years of age.

A full correction includes a number of surgical measures:

• closing the defect of the interventricular septum with a special patch;
• expansion of the exit from the stenotic area of ​​the pulmonary artery.

Postoperative period

Typically, the surgical mortality rate is less than three percent. If surgical correction is not performed, then about fifty percent of children live to be five years old and about thirty percent live to be ten years old. All children receive disability for two years, then undergo re-examination.

More patients experience positive dynamics after surgery. According to statistics, twenty-four percent of patients who have undergone radical correction of heart disease have excellent results, forty-five percent have good results, and eighteen percent have satisfactory results. Only thirteen percent of operated children have unsatisfactory results.

Note that all sick children after surgery must have endocarditis prophylaxis before any dental and surgical interventions. This is done to avoid bacteremia.

Prevention

Since tetralogy of Fallot is a congenital heart defect, preventive measures can be taken by a pregnant woman only before the baby is born. Recommended:

1. Register with the antenatal clinic before twelve weeks of gestation.
2. Come for examination to your obstetrician-gynecologist on time: once in the first trimester, once every two to three weeks of the second trimester, and once every seven to ten days of the third trimester.
3. Eat a balanced diet.
4. Avoid staying in contaminated areas.
5. Avoid active and passive smoking and intake of alcohol-containing substances.
6. Do not self-medicate.
7. Six months before planning a pregnancy, get vaccinated against rubella.
8. Avoid contact with chemicals.
9. If a pregnant woman or her relatives have a heart defect, then you should definitely notify your doctor about it.

What is prohibited for a patient after surgical correction of tetralogy of Fallot:

1. Children are not allowed to go to school for about six months.
2. Since heart disease has anatomical complications, the operated patients are limited in physical activity for life. When choosing a profession, you should focus on work without physical activity.

Summary

Tetralogy of Fallot is a complicated heart defect usually diagnosed in the first month of a baby's life. There are many reasons for the occurrence of this pathology, ranging from maternal diseases during pregnancy to genetic mutations of the fetus.

The disease requires immediate surgical correction. If it is not carried out on time, the outcome can be fatal.f

Tetralogy of Fallot ranks firmly in tenth place. The prevalence among “blue” defects is half. In medical reports and reference literature, the abbreviation CHD is often used, which is synonymous with the term “congenital heart disease.”

In the International Classification of Diseases ICD-10, it is included in the group of congenital anomalies under code Q21.3. An unusual combination of disturbances in the formation of the heart and main vessels was described in 1888 by A. Fallot as a separate syndrome. His name remains in the history of medicine.

What anomalies does the syndrome consist of, anatomical features

Includes a combination of four anomalies:

• defect in the interventricular septum;
• right-sided position of the aorta (as if “sitting astride” on both ventricles);
• stenosis or complete fusion of the pulmonary artery, it lengthens and narrows due to rotation of the aortic arch;
• pronounced right ventricular hypertrophy of the myocardium.

Among the combinations of defects with pulmonary artery stenosis and septal defects, there are 2 more forms, also described by Fallot.

The triad consists of:

• holes in the interatrial septum;
• pulmonary stenosis;
• right ventricular hypertrophy.

Pentad - adds to the first option the damaged integrity of the interatrial septum.

In most cases, the aorta receives a large volume of blood from the right side of the heart without sufficient oxygen concentration. Hypoxia is formed according to the circulatory type. Cyanosis is detected in a newborn child or in the first years of a baby’s life.

As a result, the infundibulum of the right ventricle narrows, and a cavity is formed above it, similar to an additional third ventricle. The increased load on the right ventricle contributes to its hypertrophy to the thickness of the left.

The only compensatory mechanism in this situation can be considered the appearance of a significant collateral (auxiliary) network of veins and arteries supplying blood to the lungs. The open botal duct temporarily maintains and improves hemodynamics.

Tetralogy of Fallot is typically associated with other developmental anomalies:

• non-closure of the ductus botallus;
• accessory superior vena cava;
• additional coronary arteries;
• Dandy Walker syndrome (hydrocephalus and underdevelopment of the cerebellum);
• in ¼ of patients the embryonic right aortic arch remains (Corvisart's disease);
• congenital dwarfism and mental retardation in children (Cornelia de Lange syndrome);
• defects of internal organs.

Causes

The causes of the anomaly are considered to be effects on the fetus in the early stages of pregnancy (from the second to the eighth week):

• infectious diseases of the expectant mother (rubella, measles, influenza, scarlet fever);
• taking alcohol or drugs;
• treatment with hormonal drugs, sedatives and sleeping pills;
• toxic effect of nicotine;
• intoxication with industrial toxic substances in hazardous industries;
• a hereditary predisposition is possible.

The use of pesticides in the garden without respiratory protection affects not only the health of the woman, but also her offspring

The important thing is that at a short period of time a woman may not notice pregnancy and independently provoke fetal pathology.

Types of tetralogy of Fallot

It is customary to distinguish 4 types of tetralogy of Fallot according to the characteristics of anatomical changes.

1. Embryological- narrowing is caused by anterior displacement of the septum to the left and low localization. Maximum stenosis coincides with the level of the anatomical demarcation muscle ring. In this case, the structures of the pulmonary valve are practically unchanged, moderate hypoplasia is possible.
2. Hypertrophic- to the mechanism of the previous type is added pronounced hypertrophy of the exit zone from the right ventricle and the dividing muscle ring.
3. Tubular - obstruction is caused by incorrect division in the embryonic period of the common arterial trunk, which is why the pulmonary cone (the future of the pulmonary artery) turns out to be underdeveloped, narrowed and short. At the same time, it is possible to change the valve apparatus.
4. Multicomponent- All of the above factors are partially involved in the formation.

Features of hemodynamics

The severity of the defect is determined by the degree of narrowing of the diameter of the pulmonary artery. To diagnose and determine treatment tactics, it is important to distinguish three types of anomalies:

• with complete fusion (atresia) of the arterial lumen: the most severe disorder, with a large interventricular foramen, the mixed blood of both ventricles is directed predominantly to the aorta, oxygen deficiency is pronounced, in the case of complete atresia, blood enters the lungs through the open ductus arteriosus or through collateral vessels;
• acyanotic form: with moderate stenosis, the obstacle to the blood flow from the right ventricle can be overcome by a lower pressure than in the aorta, then the blood discharge will take a favorable path from the artery to the vein, the defect variant is called “white”, since cyanosis of the skin does not form;
• cyanotic form with stenosis of varying degrees: caused by the progression of obstruction, discharge of blood from right to left; this causes a transition from the "white" form to the "blue" form.

Symptoms

The clinical picture appears:

• significant cyanosis - located around the lips, in the upper half of the body, intensifies when the child cries, feeds, strains;
• shortness of breath - has a paroxysmal nature associated with physical activity, the child takes the most comfortable “squatting” position, due to a temporary reflex additional spasm of the pulmonary artery and the cessation of blood oxygen saturation by 2 times;
• fingers in the shape of “drumsticks”;
• physical underdevelopment and weakness of children; running, outdoor games cause increased fatigue, dizziness;
• convulsions - associated with hypoxia of brain structures, blood thickening, and a tendency to thrombosis of cerebral vessels.

The form of the disease depends on the age of the child, and it determines the adequacy of compensation; in a newborn, cyanosis is visible on the face, hands and feet

There are:

• early manifestations in the form of cyanosis immediately after birth or in the first 12 months of life;
• The classic course is considered to be the manifestation of cyanosis at two to three years of age;
• severe form - paroxysmal clinical picture with shortness of breath and cyanosis;
• late - cyanosis appears only by 6 or 10 years;
• acyanotic form.

An attack of shortness of breath can occur at rest: the child becomes restless, cyanosis and shortness of breath intensify, the heart rate increases, loss of consciousness with convulsions and subsequent focal manifestations in the form of incomplete paralysis of the limbs is possible.

Diagnostics

The diagnosis is made by observing the child and the presence of objective signs. Information from relatives about development and activity, attacks with loss of consciousness and cyanosis are taken into account.

When examined in children, attention is drawn to the cyanotic nature of the lips and the altered shape of the terminal phalanges of the fingers. Rarely does a “heart hump” form.

On percussion, the borders of the heart are not changed or expanded in both directions. During auscultation, a rough systolic murmur is heard to the left of the sternum in the fourth intercostal space due to the passage of blood flow through the hole in the interventricular septum. It is better to listen to the patient in the supine position.

On the radiograph, the contours of the cardiac shadow resemble a “shoe” directed to the left

Due to the absence of the pulmonary artery arch, retraction occurs in the place where the vessels are usually located. A depleted lung appears more transparent. Enlargement of the heart to a large size does not occur.

A general blood test determines the adaptive response to hypoxia in the form of an increase in the number of red blood cells and an increase in hemoglobin.

Ultrasound diagnostics using a conventional ultrasound machine or Doppler ultrasound allows you to accurately determine changes in the chambers of the heart, abnormal development of blood vessels, the direction and magnitude of blood flow.

The ECG shows signs of right-sided cardiac hypertrophy, possible right bundle branch block, and the electrical axis is significantly deviated to the right.

Probing of the cavities of the heart with measurement of pressure in the chambers and vessels is carried out in specialized clinics when deciding on surgical treatment.

Less commonly, coronary angiography and magnetic resonance imaging may be required.

In differential diagnosis, it is necessary to exclude a number of diseases:

• transposition of the pulmonary artery causes a significant enlargement of the heart as the child grows;
• fusion at the level of the tricuspid valve promotes hypertrophy not of the right, but of the left ventricle;
• Eisenmenger's tetralogy - a defect accompanied not by fusion, but by dilation of the pulmonary artery; its pulsation and characteristic pattern of pulmonary fields are determined on an x-ray;
• stenosis of the pulmonary artery lumen is not accompanied by a “shoe” picture.

Doppler ultrasound helps to distinguish atypical forms.

Treatment

Drug therapy for a patient with tetralogy of Fallot is carried out only for the purpose of preparing for surgery or in the postoperative period. The only goal is to support the myocardium, preventing possible thrombosis after attacks and impaired coronary and cerebral circulation.

The patient is shown:

• inhalation of an oxygen-air mixture through nasal catheters or in an oxygen tent; newborns are kept in special intensive care units to reduce hypoxia;
• A solution of Reopoliglyukin, Eufillin is administered intravenously (in the absence of tachycardia);
• due to tissue acidosis, sodium bicarbonate solution is required.

It is impossible to treat a patient without surgical assistance

Operations can be:

• emergency measure of temporary assistance;
• shunt type for relieving blood flow along a new channel;
• a radical choice with correction of the ventricular septal defect and the location of the aorta.

As an emergency, the creation of an artificial connection (anastomosis) between the aorta and pulmonary artery using a prosthesis is used.

It is used as the first stage of surgical intervention for newborns and young children. It is believed that such actions allow you to prepare the child and avoid complications during further treatment, reducing the risk to 5–7%.

It is necessary to decide on the final planned correction of the defect before the age of three years. Temporary anastomoses can be performed between the subclavian and pulmonary arteries.

Radical surgery includes plastic surgery of the right ventricular exit cone, elimination of a hole in the interventricular septum, and valvotomy (dissection of an overgrown pulmonary valve). It is performed on an open heart and requires the use of a heart-lung machine.

The first days after surgery already show improvement in hemodynamics

Can surgical complications develop?

There is a risk of complications after surgery. These include:

• development of acute heart failure;
• increased thrombus formation at the anastomosis site;
• arrhythmias or atrioventricular block;
• aneurysm of the wall of the right ventricle.

The success of surgical treatment depends on the timeliness and sufficient preparation of the patient and the experience of cardiac surgeons.

What is the prognosis of patients with the defect?

Children with tetralogy of Fallot, whose parents do not agree to surgery, grow up weak and cannot move enough or play with their peers. Frequent infectious diseases (influenza, ARVI, tonsillitis, sinusitis and other sinusitis, repeated inflammations in the lungs) are typical for them. The average survival age is 12 years.

In adulthood, tuberculosis is often associated. Against the background of the defect, the prognosis of any disease is unfavorable; all diseases are severe, with cardiac decompensation and thrombosis. The most common causes of death are ischemic stroke and brain abscesses. No more than 5% of people with this anomaly live to be 40 years old. As a rule, these are people with a high degree of disability who require outside care.

In severe forms of the defect, 25% of children without surgery die in the first year of life, half in the first month.

Long-term results after surgical treatment worsen as correction of the defect is postponed to a later date. Children operated on in a timely manner grow active, develop well and tolerate physical activity.

All patients are observed by a cardiologist and consulted by cardiac surgeons. Antibiotic prophylaxis is recommended for them annually, and it is recommended to maintain oral health.

In modern medicine, treatment of patients with tetralogy of Fallot is provided by cardiac surgery clinics. After the operation, the patient's cyanosis and asthma attacks disappear. Parents should listen to the opinions of experts. The missed deadline may not be forgiven by a grown-up child.

Tetralogy of Fallot is a congenital heart defect and its abnormalities often threaten the patient’s life. As a rule, it is diagnosed in the first hours after birth, since there are characteristic clinical signs. If possible, the defect should be treated immediately.

Tetralogy of Fallot (TF) is one of the most common congenital heart defects (CHD). It is often defined as a “blue heart defect” because with this pathology, due to a shunt from right to left, insufficient blood passes through the lungs, resulting in organs and tissues not receiving enough oxygen.

Patients with tetralogy of Fallot present with cyanosis soon after birth, so early medical attention is often sought.

In case of tetralogy of Fallot, surgical intervention is mandatory, otherwise the child faces imminent death. As a rule, the operation is performed in stages, although more rapid treatment of the defect using catheter access has recently begun to be used. A successful operation often results in a favorable prognosis.

Video: Tetrad of Fallot. Congenital heart defects

Historical reference

Stensen first described the tetrad of vices in 1672; however, it was the French physician Etienne-Louis Arthur Fallot who was the first to accurately indicate the clinical and pathological features of the defects. This happened in 1888.

Although the disorder was diagnosed quite early, treatment for the defect was not implemented until the 1940s. American cardiologist Helen Brooke Taussig recognized that cyanosis progresses and inevitably leads to death in infants with tetralogy of Fallot. She hypothesized that the cyanosis was caused by insufficient pulmonary blood flow. Her collaboration with the American surgeon Alfred Blaylock led to the first advances in making life easier for sick babies.

In 1944, Blalock created the first Blalock-Taussig shunt between the subclavian artery and the pulmonary artery

The pioneering Blalock-Taussig bypass surgical technique opened a new era in neonatal cardiac surgery. The development of the Potts shunt (from the descending aorta to the left pulmonary artery), the Glenn shunt (from the superior vena cava to the right pulmonary artery), and the Waterston shunt (from the ascending aorta to the right pulmonary artery) followed.

Scott performed the first open surgery in 1954. Less than six months later, Lillehei performed the first successful open-heart reconstruction in a patient with tetralogy of Fallot. The following year, with the advent of cardiopulmonary bypass by Gibbons, another historical era in cardiac surgery was established. Since then, numerous improvements in surgical technique and myocardial preservation have been introduced to successfully treat the defect.

Description

Tetralogy of Fallot is characterized by four features:

1. Right ventricular outflow tract obstruction (infundibular stenosis)
2. Ventricular septal defect
3. Incorrect position (dextraposition) of the aorta
4. Right ventricular hypertrophy.

Sometimes an additional defect of the interatrial septum is determined, then they speak of the pentade of Fallot. The main violation of the tetrad is caused by underdevelopment of the infundibular part of the right ventricle, which leads to changes in the anterior and lower parts of the infundibular septum. This discrepancy determines the severity of the disease.

Hemodynamics in TF

Hemodynamics depend on the degree of right ventricular outflow obstruction. A ventricular septal defect usually does not act as a limiting factor, and pressure in the right and left ventricles is usually equalized.

If the obstruction is severe, blood flows inside the heart from right to left, and pulmonary blood flow may be markedly impaired. In this case, blood flow often depends on the ductus arteriosus or bronchial collaterals.

Phases of development of the defect

Depending on the severity of the disease, three phases of development of TF are distinguished:

1. The first is relatively favorable. The child does not have significant developmental delays. Lasts approximately from birth to six months.
2. The second is characterized by the presence of dyspnea-cyanotic attacks. Severe brain disorders and deaths most often develop during this phase. Lasts from six months to two years.
3. The third is considered transitional, since the clinic changes and often takes on adult features.

Some statistics and facts on tetralogy of Fallot:

• It is determined in approximately 10% of cases of congenital heart defects, that is, it occurs in 3-6 babies for every 10,000 births.
• The disease accounts for one third of all congenital heart disease in patients under 15 years of age.
• In siblings of affected parents, the incidence is 1-5%, and is more common in men than women.
• The disorder is associated with noncardiac abnormalities such as cleft lip and palate, hypospadias, and skeletal and craniofacial abnormalities.
• Tetralogy of Fallot is also seen in other mammals, including horses and rats.

Causes

The causes of most congenital heart defects are unknown, although genetic studies suggest a multifactorial etiology.

A study from Portugal showed that a polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene could be considered a susceptibility gene for tetralogy of Fallot.

Prenatal factors that increase the risk of developing tetralogy of Fallot:

• Incidence of rubella (or other viral infections) during pregnancy
• Poor nutrition of a pregnant woman
• Alcohol consumption during pregnancy and after childbirth
• Mother's age over 40 years
• Birth defects in parents
• Phenylketonuria or diabetes in a pregnant woman.

Children with Down syndrome also have a higher incidence of tetralogy of Fallot, as do infants with fetal hydantoin syndrome or fetal carbamazepine syndrome.

Clinic

The clinical features of tetralogy of Fallot directly depend on the severity of the anatomical defects. In sick infants, the following signs are most often identified:

• Difficulty feeding
• Inability to develop normally
• Bluish-pale skin color when crying or feeding
• Severe shortness of breath, usually worsening with age

Physical data includes the following:

• The height and weight of sick children does not correspond to their age
• Cyanosis of the lips and nail beds, which usually appears from birth
• After 3-6 months, fingers and toes become knotty (symptom of “drumsticks”)
• Nails become rounded (“watch glass symptom”)
• Systolic murmur is usually present anteriorly along the left sternum

Dyspnea-cyanotic attacks

They are a sign of a severe TF defect. Most often it manifests itself in the interval of six months to a year, and relative or absolute anemia is often noted.

During an attack, a strong spasm of the infundibular part of the pancreas develops, due to which venous blood enters the brain through the aorta, thereby causing severe hypoxia of the central nervous system. The oxygen level in the blood during an attack is 35% or lower. The previously heard noise almost completely disappears.

At the beginning of the development of an attack, it is determined:

• Anxiety and severe fear
• Dilated pupils
• Increasing bluishness of the skin and mucous membranes
• Increasing shortness of breath

After these symptoms, fainting and convulsions occur.

Such attacks can end in 10-15 seconds or 2-3 minutes, after which the patient becomes lethargic and adynamic. If a sufficient number of pulmonary collaterals develop before the age of 4-6 years, then attacks develop less frequently or disappear altogether. In severe cases, paresis or other disorders of brain activity occur. Also, when an attack develops, the risk of death is high.

Diagnostics

In patients with significant cyanosis in combination with a tendency to bleeding, the following changes are determined:

• Reduced blood clotting factors
• Low platelet count
• Reduced clotting factors
• Decrease in total fibrinogen
• Prolonged prothrombin and coagulation times

When analyzing arterial blood, the following is determined:

• Normal or decreased oxygen saturation
• pH and partial pressure of carbon dioxide (pCO2) are normal unless the patient is critically ill

Of the instrumental research methods used:

• Echocardiography
• Chest X-ray
• Magnetic resonance imaging
• Cardiac catheterization (in extreme cases)

Echocardiography in combination with Doppler provides the following data:

• Accurately diagnoses ductus arteriosus or atrial septal defect
• Coronary lesions are identified with some degree of accuracy
• Valve changes are easily detected

In many institutions, echocardiography is the only diagnostic test used preoperatively.

Video: Tetralogy of Fallot

Chest X-ray provides the following indicators:

• Reduction of vascular pattern in the lungs
• The classic form of “boot heart” (coeur en sabot) is a hallmark of heart disease

MRI allows you to determine:

• Clear location of the aorta, pulmonary artery and its branches
• Condition of the interventricular and interatrial septum, wall thickness of the right ventricle
• The magnitude of intracardiac pressure, gradients and blood flows

Cardiac catheterization may be helpful in any of the following cases:

• The anatomical structure of the heart and accompanying vessels cannot be fully determined by echocardiography
• Existing pulmonary artery disease is a major concern
• Pulmonary or arterial hypertension is determined

Cardiac catheterization may provide results such as the size of the pulmonary annulus and pulmonary arteries, the severity of RV outflow stenosis, and the location and size of associated anomalies and defects.

Treatment

For severe cyanosis, the following treatment methods are used:

• The child should be placed on the mother's shoulder, while his knees are pulled up. This provides a calming effect, reduces venous outflow and increases systemic vascular resistance
• Oxygen is used in limited quantities because cardiac abnormality contributes to decreased pulmonary blood flow
• Administration of morphine sulfate intramuscularly or subcutaneously can reduce ventilation dynamics and systemic venous outflow
• Phenylephrine is used to increase systemic vascular resistance
• Dexmedetomidine infusion is used, but with caution and taking into account titration rules

General anesthesia is the last resort in providing rapid care to patients with severe cyanosis with tetralogy of Fallot.

Most infants with TF require appropriate surgical intervention. Surgery is preferably performed at approximately 12 months of age. Primary repair is the ideal procedure and is usually performed in the presence of a cardiopulmonary bypass.

Palliative procedures (eg, placement of a modified Blalock-Taussig shunt) may be necessary in patients with contraindications to primary reconstruction, which include the following:

• Presence of an anomalous coronary artery
• Very low birth weight
• Small network of pulmonary arteries
• Multiple associated intracardiac anomalies

Forecast

Early surgery is not indicated for all children with tetralogy of Fallot, although without surgical intervention the natural progression of the defect often has a poor prognosis.

The progression of the disorder depends on the severity of the stenosis of the outgoing tract of the right ventricle

In the current era of cardiac surgery, children with simple forms of tetralogy of Fallot have good long-term survival with an excellent quality of life. Only in some cases the maximum capacity for physical activity is reduced.

Sudden death from ventricular arrhythmias occurs in 1-5% of patients later in life, and the cause remains unknown. It has been suggested that ventricular dysfunction may contribute to this.

If left untreated, patients with tetralogy of Fallot face additional risks that include paradoxical embolism leading to stroke, pulmonary embolism, and bacterial endocarditis. It is well known that children with congenital heart defects are prone to stroke. In most of these children, the causes of stroke were related to thromboembolism, prolonged hypotension/anoxia, and polycythemia. It is often forgotten that residual shunts or foramen ovales also contribute to the development of stroke.

Without surgery, mortality increases gradually, from 30% at 2 years of age to 50% at 6 years of age. Mortality is highest in the first year of life and then remains virtually unchanged until the second decade. In such cases, it is estimated that no more than 20% of patients reach the age of 10 years, and less than 5-10% of patients survive to the end of the second decade.

Most patients who survive to age 30 develop congestive heart failure, although they can achieve a normal life expectancy with shunts that cause minimal hemodynamic compromise. Cases of patients surviving up to 80 years have also been reported. Through the use of advanced surgical techniques over the period from 1979 to 2005. There has been a 40% reduction in mortality associated with tetralogy of Fallot.

If tetralogy of Fallot is combined with pulmonary atresia, then a worse prognosis is given. In such cases, only 50% of patients survive to 1 year and 8% can reach the age of 10 years.

Video: Elena Malysheva. Tetralogy of Fallot – congenital heart defect