Common arterial trunk. Common truncus arteriosus (TCA)
The name of this rare heart defect defines its essence. From the heart instead of two great vessels- aorta and pulmonary artery - one leaves large vessel, carrying blood into the systemic circulation, into the lungs and coronary vessels. This vessel is truncus arteriosus- did not divide, as it should, at 4-5 weeks of intrauterine life of the fetus, into the aorta and pulmonary artery, but “sitting” astride the two ventricles, carries mixed blood into both circulation circles (the ventricles communicate with each other through a huge defect interventricular septum). The pulmonary arteries to both lungs can depart from the trunk in one common vessel (and then divide into branches) or separately, when both the right and left depart directly from the trunk.
It is clear that with this defect the entire circulatory system is deeply disturbed. The flow of venous and arterial blood mixes in the ventricles. This oxygen-undersaturated mixture enters the systemic circle and the lungs under the same pressure, and the heart works with enormous load. Manifestations of the defect become obvious already in the first days after birth: shortness of breath, fatigue, sweating, cyanosis, rapid pulse, enlarged liver - in a word, all signs of severe heart failure. These phenomena may decrease in the first months of life, but in the future they will only increase. In addition, the response of the pulmonary vessels to increased blood flow leads to their changes, which will very soon become irreversible. According to statistics, 65% of children with a common arterial trunk die during the first 6 months of life, and 75% do not live to see their first birthday. For patients, even those who have reached only two or three years of age, it is usually too late to operate, although they can live up to 10-15 years.
Surgical treatment is quite possible, and its results are quite good. The most important a condition for success will be the timely admission of the child to a specialized cardiology center and performing the operation in the first months of life. Delay in these cases is like death.
If for some reason the execution radical surgery impossible, then a palliative option exists and has proven itself: applying a cuff to both pulmonary arteries originating from common trunk. This operation (see the chapter on ventricular septal defects) will protect the pulmonary vessels from increased blood flow, but it must be done very early - in the first months of life.
Radical correction of the common arterial trunk is a major intervention, performed, naturally, in conditions cardiopulmonary bypass. The arteries leading to the lungs are cut off from the common trunk, thus turning the trunk only into the ascending aorta. Then the cavity of the right ventricle is incised, and the septal defect is closed with a patch. The normal path for left ventricular blood has now been restored. The right ventricle is then connected to the pulmonary arteries using a conduit. A conduit is a synthetic tube of one or another diameter and length, in the middle of which a biological or (less often) mechanical prosthesis of the valve itself is sewn. We discussed the various designs of artificial valves and their disadvantages and advantages above (see the chapter on Ebstein's anomaly). Let's just say that as it grows, the entire sewn-in conduit can grow with its own tissue and be destroyed, and the valve can gradually become overgrown and poorly cope with its original function. In addition, the size of the conduit that can be sewn into a six-month-old child is clearly insufficient to work normally for many years: after all, synthetic tubes and artificial valves don't grow. And, no matter how large the conduit is, after a few years it will become relatively narrow. In this case, over time the question of replacing the conduit will arise, i.e. about a repeat operation, but this can happen after many years of the child’s normal life. However, the need for constant and regular cardiac monitoring should be obvious to you.
It is possible that by the time you read this, they will have already created prostheses coated on the inside with their own cells, taken in advance from the child’s tissues. For now, this is only experimental work and it will take time for it to become a clinical reality. But with today’s dizzying pace of scientific development, this is quite possible in the near future.
OSA is characterized by the fact that a single main vessel with a common semilunar valve departs from the right and left ventricles, from which the branches of the aortic arch and PA originate. Under the common semilunar valve of this vessel there is a large VSD.
Anatomical classification of OSA according to Van Praagh:
- Type A1- the pulmonary arteries begin from a short trunk of the pulmonary artery, extending from the wall of the pulmonary artery (common arterial trunk).
- Type A2- pulmonary arteries begin as independent ostia from ascending department OAS.
- Type AZ- one of the pulmonary arteries, usually the right, starts from the PDA, the second is supplied with blood through the PDA or a collateral vessel.
- Type A4- a combination of OSA with a break in the aortic arch (the descending aorta is supplied with blood through the PDA).
In OSA, only one branch leaves the heart arterial vessel, through which coronary hemodynamics, hemodynamics of the ICC (pulmonary circulation) and BCC (systemic circulation) are ensured. Since mixed blood enters OSA, cyanosis is the main and first symptom of the disease. Otherwise, the pathophysiology of the defect will depend on the presence of concomitant anomalies (rupture of the aortic arch, malformations of the coronary arteries) and the type of origin of the PA (pulmonary artery) from the OSA. Depending on this, both enrichment and depletion of the ICC may be observed (in rare cases), varying degrees severity of heart failure associated with both volume overload of the ventricles and deficiency coronary blood flow. OSA valve insufficiency is continuously progressing.
Most patients die within the first two weeks of life, 85% by the end of the first year of life. OSA is a component of DiGeorge syndrome in 33% of cases. The life prognosis of patients with OSA is unfavorable.
CLINIC
A. Clinical manifestations of the disease:
Cyanosis of varying severity;
Signs of heart failure (shortness of breath) from the first days after birth.
b. Physical examination:
High pulse pressure;
Pronounced pulsation of the precordial region, the apical impulse is significantly shifted to the left;
Rough (2-4/6) systolic murmur associated with the presence of a VSD, which is better heard along the left edge of the sternum;
With hypervolemia of the ICC, a rough sound is heard in the projection of the apex. diastolic murmur(“rumble”), which can be combined with a “gallop rhythm”;
Gentle diastolic murmur of OSA valve insufficiency.
DIAGNOSTICS
- Electrocardiography
ECG signs of biventricular hypertrophy (hypertrophy of one of the ventricles is less common);
Rarely LA hypertrophy.
- Echocardiography
Diagnostic criteria:
Detection of one wide vessel extending from both ventricles;
Detection of the pulmonary artery arising from the OSA;
The presence of mitral-lunar fibrous continuation;
Presence of only one semilunar valve.
TREATMENT AND OBSERVATION
- Monitoring and treatment of patients with uncorrected OSA
A. Before surgery, all patients must undergo active treatment heart failure (diuretics, digoxin).
b. Since OSA is a manifestation of DiGeorge syndrome in 33% of cases, the following recommendations should be followed:
Constant monitoring of serum potassium and magnesium levels and, if necessary, their correction,
Treatment and prevention of streptococcal and pneumococcal infections, taking into account the presence of thymus-dependent immunodeficiency;
Avoid immunization with live vaccines.
V. Prevention bacterial endocarditis according to indications.
- Surgery
Indications for surgical treatment:
Diagnosis of OSA - absolute reading to surgical treatment.
Contraindications to surgical treatment:
High pulmonary hypertension (TLC > 10 U/m2 initially and > 7 U/m2 after the use of vasodilators);
The presence of absolute contraindications due to concomitant somatic pathology.
Surgical tactics
Ideally, OSA should be diagnosed within the first hours after birth. In this case, planned surgical treatment is carried out during the first week of life. In case of late diagnosis, it is necessary to evaluate OLC.
The procedure of choice is primary radical correction.
PA narrowing, even if anatomically possible, is not clinically effective.
Surgical technique
Artificial circulation. Bicaval cannulation and OSA cannulation. The pulmonary arteries are isolated and placed on tourniquets. During cardioplegia, they are briefly clamped in order to direct the cardioplegic solution into the coronary arteries. Prolonged compression of the pulmonary arteries can damage the lungs. To avoid shunting the flow from the aortic cannula into the PA, the aortic clamp should be placed above the PA orifices. When relieving cardioplegia through an incompetent truncal valve, it is necessary to open the lumen of the coronary artery, and perfusion of the cardioplegic solution is carried out directly into the ostia of the coronary arteries.
The LA is cut off from the wall of the OAS. The wall defect is sutured or repaired with a xeno/autopericardial patch. VSD repair is performed through a ventriculotomy in the RVOT (pulmonary artery). The plastic material is Dacron. After VSD repair, prosthetics of the trunk and valve of the pulmonary artery is performed with a valve-containing conduit. First of all, a distal anastomosis is formed between the conduit and the PA. Plastic surgery of the OSA is performed, reducing its diameter, and plastic surgery of the truncal valve is performed to prevent its insufficiency. Doc prosthetics using any known method leads to unsatisfactory results. The correction is completed by forming a proximal anastomosis between the valve-containing conduit and the RVOT through ventriculotomy. IN postoperative period The development of “pulmonary crises” is typical. Despite the wide options for drug treatment, it is advisable to leave an interatrial fistula with a diameter of 3 mm to ensure systemic hemodynamics when pressure in the pulmonary artery increases (especially if surgical treatment is performed after the age of 6 months).
Specific complications surgical treatment:
RV failure (pulmonary crises);
Residual pulmonary hypertension;
Atrioventricular nodal ectopic tachycardia;
Conduit dysfunction.
Postoperative follow-up
- Postoperative monitoring is carried out every 4-6 months for life. The condition of the truncal valve and conduit is monitored, and the severity of arrhythmias is assessed.
- Prevention of bacterial endocarditis is carried out according to indications throughout life.
- Physical education and sports are not recommended.
Online Tests
- Is your child a star or a leader? (questions: 6)
This test is intended for children aged 10-12 years. It allows you to determine what place your child occupies in the group of peers. To correctly evaluate the results and get the most accurate answers, you should not give a lot of time to think; ask your child to answer what first comes to his mind...
What is the Common Arterial Truncus -
A physiological deviation in which the primitive trunk is not divided by the septum into the pulmonary artery and aorta, while a large single arterial trunk is formed. It is located over the perimembranous infundibular ventricular septal defect.
Due to this defect, mixed blood enters the systemic circulation, the brain and lungs of a person. The defect is manifested mainly by cyanosis, sweating, eating disorders, etc. Cardiac catheterization or echocardiography is used for diagnosis. In most cases, prevention of a disease such as endocarditis is necessary.
Among congenital heart defects, the common truncus arteriosus accounts for, according to statistics, from 1 to 2% (among children and adults). More than a third of patients have palatocardiofacial syndrome or DiGeorge syndrome.
Four types of disease:
- Type I - the pulmonary artery arises from the trunk, then divides into the left and right pulmonary arteries.
- Type II - the left and right pulmonary arteries arise independently from the posterior and lateral sections of the trunk, respectively.
- Type III - the same as type II.
- Type IV - arteries arise from the descending aorta and supply blood to the lungs; this is a severe form of tetralogy of Fallot (as clinicians believe today).
The child may experience other anomalies:
- coronary artery anomalies
- trunk valve insufficiency
- double aortic arch
- AV communication
These abnormalities increase the chance of death after surgery. In the first type of disease, the consequences include heart failure, slight cyanosis, and increased blood flow to the lungs. In the second and third types, a stronger expression is observed, and HF is observed in rare cases, in contrast to the first type, and the pulmonary blood flow may be normal, or there will be a slight increase in it.
What provokes / Causes of the Common truncus arteriosus:
Common truncus arteriosus is a congenital heart defect - it occurs when the fetus is in the womb. It can be caused by the effect on the body of a pregnant woman negative factors, especially in the first trimester of pregnancy. Among hazardous factors, provoking the disease, distinguish diseases of the pregnant woman. Moreover, the unborn child develops not only congenital heart defects, but other life-threatening diseases.
Negatively affects the fetus, increasing the risk of truncus arteriosus in the newborn, chronic alcoholism mother. If a woman had rubella during pregnancy ( infectious disease), it with high probability will negatively affect the development of the fetus. Among the negative factors are:
- flu
The disease is provoked physical factors, often this is the effect of radiation. This factor can cause deformities and mutations in the fetus. This also includes radiation research methods, a prime example being x-rays. Research of this type should only be carried out in as a last resort, it is better to use other research methods.
Harmful and chemical factors:
- nicotine (smoking: active and passive)
- drinking alcohol
- part of medicines
- drugs
Pathogenesis (what happens?) during the Common truncus arteriosus:
The common arterial trunk appears due to disruption of the formation of great vessels on early stage embryogenesis (5-6 weeks of fetal development) and the absence of division of the primitive trunk into the main main vessels - the aorta and pulmonary artery.
Due to the absence of a normal septum between the aorta and pulmonary artery, they communicate widely. Therefore, the common trunk departs from both ventricles at once, and arterial and deoxygenated blood to the heart, lungs, liver and other organs of the child. The pressure is the same in the ventricles, truncus arteriosus and pulmonary arteries.
In most cases, the development of the septum of the heart is delayed, so the heart may consist of three or two chambers. The valve of the common truncus arteriosus may have one, two, three or four leaflets. IN frequent cases deficiency develops or. An extensive ventricular septal defect also plays a role in pathogenesis.
Symptoms of the Common truncus arteriosus:
In type I, the infant experiences symptoms of heart failure:
- eating disorder
- tachypnea
- excessive sweating
Also typical symptom The first type of common truncus arteriosus is cyanosis in mild form. This and the above listed signs appear when the baby is only 1-3 weeks old. At II and III type cyanosis is more pronounced, and heart failure is observed in extremely rare cases.
Physical examination reveals the following symptoms of the common arterial trunk:
- loud and single II tone and ejection click
- increase in pulse pressure
- increased heart rate
A holosystolic murmur of intensity 2-4/6 is heard along the left edge of the sternum. At the apex, with an increase in blood flow in the pulmonary circulation, in some cases a murmur is heard on the mitral valve in the middle. With truncus arteriosus valve insufficiency, a decreasing high-pitched diastolic murmur is heard. It is heard in the third intercostal space to the left of the sternum.
Diagnosis of the Common truncus arteriosus:
Diagnosis of common arterial valve in infants requires clinical data, which are described in detail above. X-ray data of organs are taken into account chest and data obtained from the electrocardiogram. Two-dimensional echocardiography with color Dopplercardiography helps to clarify the diagnosis. Before surgery, there is often a need to clarify other abnormalities that the patient may have, in addition to the disease in question. Then cardiac catheterization is performed.
X-ray methods make it possible to detect cardiomegaly (can be either slightly or strongly expressed), the pulmonary pattern is enhanced, the aortic arch is located to the right in a third of patients, the pulmonary arteries are located relatively high. With significant gain, gain pulmonary blood flow Signs of left atrium hypertrophy may appear, which is also taken into account during diagnosis.
The most current diagnostic methods
EchoCG- echocardiography is a method that is a study of the heart using ultrasound. With a common truncus arteriosus, a direct connection of one or two pulmonary arteries with a single truncus arteriosus is identified.
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When two main vessels leaving the heart (aorta and pulmonary arteries) fuse into a single highway, which ensures the flow of blood to all tissues of the body, a common arterial trunk is formed. This congenital pathology baby. Correction of the defect is required by surgical intervention.
Read in this article
Reasons for the development of congenital heart disease of the common truncus arteriosus in the fetus
The formation of large vessels occurs in the 3rd to 5th decade of pregnancy. Due to the action of damaging factors at this time or the presence genetic defects the common trunk is not divided into the aorta and pulmonary artery. There remains a major message between them. Such a vessel comes from two ventricles at once, the blood in it consists of venous and arterial, it nourishes the heart, brain and everything internal organs. The same pressure is recorded in all chambers of the heart and main vessels.
The heart of a newborn may have three or even two chambers, since the development of the cardiac septum is also inhibited. One of typical signs with a four-chambered heart is big square defect of the interventricular wall. The valve of this vessel has from one to four leaflets; narrowing or insufficiency of its function is often diagnosed.
The reasons that provoke developmental anomalies are:
- maternal diseases - influenza, herpes, rubella, measles, chicken pox, cytomegaly, syphilis, rheumatism, tuberculosis, diabetes mellitus;
- action external environment– contaminated water, air, occupational hazards from mother or father;
- one of the parents or both has alcoholism, drug addiction, age under 16 or over 45;
- taking pregnant hormones, sulfonamides, anticonvulsants and psychotropic drugs, cytostatics, antitumor antibiotics;
- cases of developmental defects in the family;
- toxicosis, threat of abortion.
Symptoms in a newborn
If the pulmonary artery has a wide lumen, then the child is in an extremely serious condition from the first minutes after birth due to the fact that blood flows into the lungs under high pressure. This leads to critical circulatory disorders and death of the newborn. If the baby nevertheless survives, then he has a severe form. Clinical signs the common arterial trunk can be:
- lethargy;
- low physical activity;
- fatigue when feeding;
- poor weight gain;
- shortness of breath and cyanosis even at rest, worsening with light exertion;
- sweating;
- rapid heartbeat;
- enlarged heart and liver;
- heart hump, fingers in the form drumsticks, nail plates are like watch glass.
However, when the pulmonary artery is narrowed, the symptoms are less severe, since this protects the small circle from excessive overflow, allowing such children to live to 16 or even 40 years of age (this happens extremely rarely). Manifestations of pathology in such a situation are due to the development of circulatory failure due to mixed type(right and left ventricular).
In children's and school age the child is often sick, against the background colds or recurrent pneumonia, the condition worsens sharply.
Types of pathology
Depending on the branching options of the pulmonary arteries, there are four types of this congenital malformation:
- departs common vessel, and then it splits into 2 branches;
- two branches come from back wall;
- the right and left vessels arise from the corresponding lateral sides;
- there are no arteries of the lungs, and the blood enters through the bronchial branches of the aorta (a type of Fallot's disease).
General main trunk located above both ventricles or predominantly above one. Anatomical shape of this vessel and the degree of narrowing of the pulmonary artery leads to the appearance of three types of circulatory disorders:
- increased blood flow to the lungs, progressive pulmonary hypertension and cardiac decompensation, resistant to therapy;
- pulmonary blood flow is slightly higher than normal, shortness of breath and cyanosis of the skin during exertion are noted, circulatory failure is absent or not higher than grade 1;
- poor blood flow to the lungs due to a narrowed artery, intense and stable cyanosis, respiratory failure, oxygen starvation body.
Manifestations on ultrasound and other diagnostic methods
Expert opinion
Alena Ariko
Expert in Cardiology
If the doctor is sufficiently qualified, the detection of the common trunk occurs at the stage of antenatal (prenatal) diagnosis. At 25 - 27 weeks of pregnancy, you can see a large duct in the center or shifted to one of the ventricles. At the same time, concomitant anomalies in the development of the aorta, fusion of the valves, hypoplasia or absence of the ventricles of the heart are often identified. Most often, in such a situation, a woman is recommended to terminate pregnancy artificially.
If the diagnosis is carried out in a newborn, then the following signs are taken into account:
- – more often in systole, increased 2nd tone;
- – overload of all parts of the heart and deviation of the axis to the right side;
- X-ray examination– the configuration of the heart resembles a ball, the ventricles are enlarged, the shadows of the great vessels and branches of the pulmonary artery are expanded;
- Ultrasound of the heart – main method to identify the defect, the defect of the ventricular septum and the main trunk extending from it are visualized;
- – the catheter easily passes from the right ventricle into the common trunk and aorta, the pressure is the same in the parts of the heart, when the arteries of the lungs are narrowed, there is a pressure difference, the degree of blood oxygen saturation is below normal (with high hypertension in the lungs it decreases to extremely low values);
- aortography– helps determine the level of branch of the pulmonary arteries and valvular narrowing or insufficiency.
Treatment of the common truncus arteriosus
Drug therapy is ineffective. The newborn is placed in an incubator, where body temperature is maintained and blood circulation and blood composition are adjusted. At critical condition In an infant, the first stage of the operation consists of narrowing the lumen of the artery of the lungs. After a few months, a radical correction is carried out:
- separation of the pulmonary branches from the common vessel;
- installation of a prosthesis with a valve in the right side of the heart;
- plastic surgery of the hole in the septum between the ventricles.
The success of treatment is determined by the severity of hypertension in the pulmonary vessels and the presence of other anomalies in the structure of the heart. No surgery until adolescence Approximately 15% of children survive. After surgery, the ten-year survival rate reaches 70%; replacement of the prosthesis may be necessary.
Watch the video about surgical treatment common arterial trunk:
Prevention
It is possible to prevent the development of heart defects when planning pregnancy, undergoing by future parents medical genetics in cases of congenital anomalies in the family. During pregnancy it is necessary to exclude independent use any medications, alcohol consumption, smoking, contact with toxic compounds at work.
Sick with it congenital defect hearts should be under the supervision of a cardiologist all their lives, giving rise to preventive courses of therapy. They are recommended to take antibiotics even for minor surgical procedures to prevent infectious complications. When compensating for heart failure, it is important that the daily routine includes:
- rest during the day from 1 to 2 hours;
- sleep at least 8 hours at night;
- walk in the fresh air;
- breathing exercises;
- physical therapy classes;
- work with feasible intensity.
Expert opinion
Alena Ariko
Expert in Cardiology
It is necessary to warn the patient that complete immobility and sudden, rapid movements are equally harmful; it is especially dangerous to climb stairs or a natural hill at high speed.
Whenever possible, contact with infected patients should be avoided during epidemics, as well as travel with sudden changes climate. Diet food provides:
- mandatory calculation of calorie content depending on the degree motor activity(for example, with semi-bed rest - no more than 30 Kcal per 1 kg of weight);
- fractional meals – 5 times a day in small portions;
- preparing easily digestible dishes;
- sufficient content of lean protein and vitamins;
- in the presence of edema, you need to reduce the amount of salt and water, periodically prescribe fasting days on milk, rice, potatoes.
The common arterial (aortopulmonary) trunk is congenital anomaly development, in which one large vessel comes from the heart. It collects blood from the two ventricles and then enters the pulmonary vessels and arterial network great circle blood circulation
There is always a septal opening in the interventricular part. Newborns are most often in serious condition due to blood overflow pulmonary system. Increasing cardiac decompensation leads to the death of the child without early surgery.
Read also
In modern diagnostic centers Heart defects can be detected by ultrasound. In the fetus it is visible starting from 10-11 weeks. Congenital signs are also determined using additional methods examinations. Errors in determining the structure cannot be excluded.
Common truncus arteriosus - CHD, in which one large vessel arises from the base of the heart through a single semilunar valve and provides coronary, pulmonary and systemic circulation. Other names: common trunk, common aortopulmonary trunk, persistent truncus arteriosus. The first description of the vice belongs to A. Buchanan (1864). This defect accounts for 3.9% of all congenital heart defects according to the results of pathological studies and 0.8-
- 7% - according to clinical data.
- - origin of the right, left or both pulmonary arteries from the lateral walls of the truncus; IV - absence of pulmonary arteries, due to which the blood supply to the lungs is carried out through the bronchial arteries arising from the descending aorta. This variant is not currently recognized as a type of true truncus arteriosus, in which at least one branch of the pulmonary artery must arise from the truncus. Thus, we can talk mainly about two types of defects: I and II-III.
cinosis. The valve leaflets of the common trunk are fibrously connected to the mitral valve, so it is considered to be primarily aortic.
The location of the truncus above the ventricles is important when selecting patients for radical correction of the defect. In the observations of F. Butto et al (1986), in 42% it was located in equally over both ventricles, in 42% - predominantly over the right and 16% - predominantly over the left ventricle. In these cases, the exit from the ventricle, which is not connected to the trunk, is the VSD. According to other observations, the truncus departs from the right ventricle in 80% of cases, while closure of the VSD during surgery leads to subaortic obstruction.
A VSD is always present with the common truncus arteriosus; it does not have an upper edge, lies directly under the valves and merges with the mouth of the truncus; there is no infundibular septum.
This defect is often combined with anomalies of the aortic arch: break, atresia, right-sided arch, vascular ring, coarctation.
Other concomitant CHDs include open general at
rioventricular canal, single ventricle, single pulmonary artery, anomalous drainage of the pulmonary veins. Of the extracardiac defects, there are anomalies gastrointestinal tract, urogenital and skeletal anomalies.
Hemodynamics. Blood from the right and left ventricles enters a single vessel through the VSD; the pressure in both ventricles, truncus and branches of the pulmonary artery is equal, which explains early development pulmonary hypertension; The exception is cases with stenosis of the pulmonary artery orifice and its branches or their small diameter. The right ventricle with the common arterial trunk overcomes systemic resistance, which causes hypertrophy of its myocardium and dilatation of the cavity. The hemodynamic features of the defect are determined largely by the state of blood circulation in the pulmonary circle. The following options can be distinguished.
- Increased pulmonary blood flow with low resistance in the pulmonary vessels, pressure in the pulmonary arteries is equal to systemic pressure, which indicates high pulmonary hypertension. It is more common in young children and is accompanied by heart failure that is resistant to therapy. Cyanosis may not be present because a large number of blood is oxygenated in the lungs and mixed in the ventricles due to big size VSD. Large discharge into the common trunk, especially with a multi-leaf valve, contributes to the appearance of valvular insufficiency over time, which further aggravates the severity clinical course diseases.
- Normal or slightly increased pulmonary blood flow due to new resistance in the pulmonary vessels, preventing a large discharge of blood into the common trunk. There is no heart failure; cyanosis appears with exercise.
- Reduced pulmonary blood flow (hypovolemia) can occur with narrowing of the mouth of the trunk or branches of the pulmonary artery or with progressive sclerosis of the pulmonary vessels. Severe cyanosis is constantly observed, since a small part of the blood is oxygenated in the lungs.
Clinic, diagnostics. By clinical manifestations children with this defect resemble patients with a large VSD. The leading symptom should be considered shortness of breath of the tachypnea type up to 50-100 per minute. In cases of reduced pulmonary blood flow, shortness of breath is significantly less pronounced. Cyanosis in the common truncus arteriosus varies: it is minimal or absent with increased pulmonary blood flow, expressed with sclerotic changes in the pulmonary vessels (Eisenmenger reaction) or pulmonary artery stenosis. In the latter cases, he supported
is led by the development of symptoms of “watch glasses” and “drumsticks”, iolicythemia. With cardiomegaly, a heart hump appears. Heart sounds are loud, the second heart sound above the pulmonary artery is accentuated, can be single or split if there are more than three valves. An apical systolic click is often detected. A rough, continuous murmur of VSD is determined in the third and fourth intercostal spaces on the left near the sternum; at the apex there may be a mesodiastolic murmur of relative stenosis mitral valve- a sign of hypervolemia of the pulmonary circulation. If the structure of the leaflets causes a stenotic effect in the second and third intercostal spaces, an ejection-type systolic murmur is heard on the left or right. With the development of trunk valve insufficiency, a protodiastolic murmur appears along the left edge of the sternum. Heart failure is expressed in the right and left ventricular type, up to the picture pulmonary edema; it is less or absent with hypovolemia of the pulmonary circulation and sclerotic changes in the pulmonary vessels.
There are no specific electrocardiographic characteristics of the defect. Electric axis the heart is located normally or deviated to the right (from -(-60 to 4-120°). In half of the patients, enlarged right atrium, right ventricle (in the lead QRS complex type R or qR), less often both ventricles. With pulmonary hypertension, the ECG shows signs of “strain” type overload in the right precordial leads (decrease in the ST interval by 0.3-0.8 cm, negative T waves in the leads
Vi-z).
On FCG, tones of normal amplitude are visible at the apex, aortic clicks are recorded in the second intercostal space; The second tone is often single, but can be wide and consist of several high-amplitude components; Pansystolic murmur is recorded, sometimes high-frequency with a maximum in the third and fourth intercostal spaces on the left, and protodiastolic murmur is a sign of valvular insufficiency.
On a chest x-ray, the pulmonary pattern is usually strengthened, with stenosis of the pulmonary artery mouth it is depleted on both sides, with stenosis or atresia of one of the branches - on one side, with the sclerotic phase of pulmonary hypertension - it is depleted mainly along the periphery and strengthened in the hilar zone. The heart is often moderately enlarged (cardiothoracic ratio - from 52 to 80%), may become ovoid with a narrow vascular bundle, which resembles transposition of the great vessels, but with a straighter upper left edge. As a rule, both ventricles are enlarged. Sometimes the heart is similar in shape to that of tetralogy of Fallot, there is a characteristic wide base of the vessel with an S-shaped course. The right-sided location of the aortic arch is found in 3 patients, which, in combination with increased pulmonary blood flow and cyanosis, should raise suspicion of a common arterial trunk. A certain diagnosis
the high position of the left pulmonary artery may have a nostic significance.
A characteristic M-echocardiographic sign of the defect is the absence of a continuous septal-aortic (anterior) continuation, while a wide vessel “sits astride” the VSD. With the predominant departure of the common trunk from the left ventricle, the posterior (mitral-lunar) continuation is preserved. When the arterial trunk communicates predominantly with the right ventricle, a violation of the anterior and posterior continuous continuations is recorded. Other M-echocardiographic signs of the defect are: inability to determine the second semilunar valve; diastolic flutter of the anterior leaflet of the mitral valve due to insufficiency of the semilunar valve of the common truncus arteriosus; dilatation of the left atrium.
A two-dimensional echocardiographic examination in the long axis projection of the left ventricle reveals a wide great vessel crossing (“ridden”) the septum, a large VSD, the posterior continuation is preserved. In a short projection at the level of the base of the heart, the ventricular outflow tract and the pulmonary valve are not identified. From the suprasternal approach, in some cases, it is possible to determine the origin of the pulmonary artery or its branches from the truncus.
Catheterization of the cardiac cavities and angiocardiography have crucial in diagnostics. Venous catheter enters the right ventricle, where the pressure is equal to the systemic one, but in combination with an increase in blood oxygen saturation indicates
about VSD. Next, the catheter is freely passed into the truncus, where the pressure is the same as in the ventricles. Blood oxygen saturation in the common arterial truncus usually ranges from 90-96% in cases with hypervolemia. The difference in oxygen saturation of the blood of the pulmonary artery and truncus does not exceed 10%. A decrease in blood oxygen saturation to 80% indicates sclerotic changes in the pulmonary vessels and inoperability of patients. When inserted contrast agent in the right ventricle the common arterial trunk is visible (better in the lateral projection), from which the coronary vessels and the pulmonary artery (or its branches) depart. Aortography allows you to finally confirm the origin of the true pulmonary arteries directly from the trunk, detail the type of defect and determine the degree of insufficiency of the truncus valve (Fig. 66).
Differential diagnosis should be carried out in cases without cyanosis with VSD, in cases of cyanosis - with tetralogy of Fallot (especially in pulmonary atresia), transposition of the great vessels, Eisenmenger syndrome.
Course, treatment. The course of the defect is severe from the first days of the patient’s life due to severe heart failure and
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pulmonary hypervolemia; with cyanosis, the severity of the patient's condition is determined by the degree of hypoxemia. Most children die in the first months of life and only "/5 survive the first year, and 10% survive until the 1st-3rd decade)
