Atrial septal defect. Ventricular septal defect - description, causes, symptoms (signs), diagnosis, treatment Qp qs calculation
When analyzing the pathology of the heart various special concepts are used, the most important of which are discussed in this section.
Atresia and hypoplasia. The term "atresia" is used in cases where any structure is not formed. It is most often used in relation to valves or vessels, which may be completely absent or may be replaced by a membrane (valve) or fibrous tissue (vessel). The term "hypoplasia" reflects a decrease in the diameter, length or volume of the cardiac structure.
Distensibility, dilatation, ventricular hypertrophy. Compliance determines the degree of resistance to blood flow in the cavity of the ventricles. In newborns, the right ventricle is less compliant, which determines the great resistance to the flow of blood into it from the right atrium and the relatively high diastolic pressure in it.
dilatation is an increase in cavity greater than two standard deviations for a given surface area of the child's body and occurs in response to acute or chronic volume overload. Hypertrophy characterizes the degree of increase in the total mass of the myocardium or intracellular structures compared to the norm. Outwardly, it is manifested by a thickening of the wall of the heart chamber, sometimes to the detriment of its volume.
Dilation and hypertrophy can be combined in various combinations and constantly accompany congenital heart defects.
The volume of circulating blood.
This concept is used in relation to both large (BKK) and small (MKK) circles. blood circulation. The state of a healthy child is characterized by normovolemia - a normal volume of circulating blood. In cases of excessive blood flow from the placenta during clamping of the umbilical cord, systemic hypervolemia may occur. With congenital heart defects, changes most often relate to pulmonary blood flow. Excessive blood flow to the pulmonary artery system is accompanied by hypervolemia of the ICC, reduced blood flow - hypovolemia. Normal inflow in combination with difficult outflow leads to hypervolemia of the ICC of a congestive nature.
Increasing pressure in pulmonary artery system referred to as ICC hypertension. It can be of arterial origin (excessive blood flow), a consequence of venous stasis (difficulty in outflow) or damage to the wall of the pulmonary vessels by an obstructive process.
Even significant hypervolemia ICC may not lead to high pulmonary hypertension (for example, with an atrial septal defect), and hypertension, in turn, may not be combined with hypervolemia, and even vice versa, be accompanied by hypovolemia (in cases where high pulmonary vascular resistance limits volumetric blood flow through the lungs ). A clear distinction between these concepts is important for the analysis of the processes occurring during the development of pathological conditions in newborns and infants.
The volume of blood flow and the size of the shunt.
These parameters are used to characterize the UML and basins of small and large circles of blood circulation. The volume of blood flow is defined in milliliters or liters per minute and in most cases is calculated per square meter of body surface. In healthy newborns, the normalized systemic blood flow is 3.1+0.4 l/min/m2.
If there is bleeding from a large circle of blood circulation to a small one or vice versa, the volume of this discharge is calculated using the formulas:
Shunt from left to right = Qp - Qs; Shunt from right to left = Qs - Qp,
where Qp is the volume of blood flow in the pulmonary circulation, Qs is the volume of blood flow in the systemic circulation.
Since in practice the exact measurement of volumetric blood flow, associated with the analysis of oxygen consumption, is difficult, the ratio of pulmonary and systemic blood flows (Qp / Qs) is more often used. With a 1:1 ratio, there is no shunt or it is the same in both directions. In cyanotic malformations, pulmonary blood flow is reduced and Qp/Qs can be, for example, 0.8:1. With resets from left to right, Qp/Qs increases, can reach 2:1 or more, determining the indications for surgery. The calculation of these parameters is possible using an echocardiographic study.
Clinicians working in the field of congenital heart disease and pediatric heart disease need a unified nomenclature that can be used to classify this group of diseases at any age in patients with congenital heart disease. Any classification is subject to refinement and refinement over time. The World Health Organization (WHO) in 1970 approved the International Classification of Congenital Heart Diseases, which was used in the ICD 10th revision. However, the HTS group in ICD-10 was not detailed enough and contained many recurring conditions. Therefore, in the 1990s. The Society of Thoracic Surgeons (STS), the European Association for Cardiothoracic Surgery (EACTS), and the European Association for Pediatric Cardiology (AEPC) independently developed the CHD nomenclature.As a result, the International Cardiac Surgical Nomenclature of CHD was published in 2000, and the European Pediatric Cardiac Code was published at the same time. To bring these nomenclatures together, an International Working Group known as the Nomenclature Working Group was created. In 2005, a unified nomenclature of congenital heart defects and heart disease in children (International Pediatric and Congenital Cardiac Code - IPCCC, http:// www.ipccc.net) appeared, based on the two previous nomenclatures. According to the IPCCC, each defect is encoded with a six-digit numeric code. The need to create this system is due to the need to analyze multicenter diagnostic and therapeutic studies and risk stratification, the introduction of electronic technologies for maintaining medical records in medical practice based on the use of universal coding designations, the need for long-term follow-up of such patients from birth and at any age. In 2006, the International Association for Further Work on the Nomenclature of Congenital Heart Disease and Heart Disease in Children was established in Canada, consisting of three working groups. The Nomenclature Development Group creates, distributes, updates and maintains international classification codes. It provides access to information about these codes for pediatric, cardiac and cardiac surgery professional associations, organizations of the health system, including government health authorities. As part of the association, there is a group for the development of disease definitions and a group for archiving video images for a new international classification. These photo and video images are presented by the data of pathomorphological and instrumental studies (echocardiography, angiography, MSCT and MRI, intraoperative photo and video recordings). The International Association for the Development of a Nomenclature for Congenital Heart Disease and Pediatric Heart Disease works in collaboration with the experts leading the development of the International Classification of Diseases 11th Revision, under the leadership of WHO, as well as with the specialists of the International Organization for the Development of Standards of Medical Terminology (Systematized Nomenclature of Medicine - SNOMED).
The list of the new international nomenclature includes all known types of IPU with maximum accuracy and completeness. At the same time, this complex list covers more than 10,000 codes, divided into 7 main groups, and it is very difficult to find a specific vice code in it. In 2011, a group of pediatric cardiologists from France, based on the analysis of a large amount of their own data, proposed a convenient regrouping of the IPCCC list with 10 main categories and 23 subcategories, which facilitates the practical use of the new nomenclature for use in practical work, as well as for epidemiological and research purposes.
Cardiologists usually use in practice a working classification of CHD depending on the types of hemodynamic disorders, according to which heart defects are divided into several main groups. The most formidable clinical disorders in congenital heart defects are hypoxemia, pulmonary hypertension, and heart failure.
Hypoxemia is most often caused by intracardiac right-left shunt; in this case, patients develop distal or diffuse cyanosis due to an increased content of hemoglobin in the capillary bed. Clinically, cyanosis is seen if the concentration of reduced hemoglobin in arterial blood is more than 3-5 g/dL. Cyanosis varies in intensity from bluish to purple color of the mucous membranes and skin. Depending on the presence or absence of this feature, pale CHD (without cyanosis) and blue (with cyanosis) are distinguished. The most common CHD without cyanosis include VSD, ASD, PDA, coarctation of the aorta, aortic stenosis, atrioventricular canal, the more rare ones are interrupted aortic arch, mitral stenosis, mitral valve insufficiency. Heart defects without cyanosis, in turn, are divided into two subgroups according to the types of pathophysiological disorders: 1) CHD with a left-right shunt (defects of the septal walls of the heart, patent ductus arteriosus, atrioventricular canal, aortopulmonary window) and 2) CHD with obstruction of the left departments of the heart (coarctation and stenosis of the aorta, interrupted aortic arch, mitral stenosis).
The most common CHD with cyanosis is tetralogy of Fallot, severe stenosis or atresia of the pulmonary artery, transposition of the main arteries, tricuspid valve atresia, truncus arteriosus, total anomalous pulmonary venous drainage, hypoplastic left heart syndrome, Ebstein's disease.
Among CHD with cyanosis, two subgroups can also be distinguished: 1) with depletion of pulmonary blood flow (Fallot's tetrad, pulmonary artery atresia, pulmonary artery stenosis, tricuspid valve atresia, Ebstein's disease) and 2) with an increase in pulmonary blood flow, i.e. pulmonary hypertension (transposition of the main arteries, common truncus arteriosus, total anomalous pulmonary venous drainage, hypoplastic syndrome of the left heart).
This subdivision of the CHD is conditional, since in pale CHD with a very large left-to-right shunt, hypoxemia may occur due to pulmonary edema or pulmonary vascular sclerosis, and as a result, the direction of the intra-cardiac shunt will change to right-to-left. At the same time, pulmonary hypertension is characteristic of both defects without cyanosis and a number of cyanotic defects.
Most often, pulmonary hypertension occurs with defects with a left-to-right shunt. In the postnatal period, in a healthy child, the same volumes of blood flow through the systemic and pulmonary circulations, while the vascular resistance in the systemic circulation is approximately 6 times greater than in the pulmonary circulation. This is associated with higher values of systemic arterial pressure and systolic pressure in the left ventricle. Due to the difference in pressure, in the presence of a pathological communication between the sections of the heart, blood moves from the left sections to the right. The direction and size of the volume of shunted blood depend on the size of the defect and the pressure on both sides. Accurate determination of blood volumes in the large and small circles requires invasive methods for analyzing oxygen consumption, therefore, the calculation of the ratio of these volumes (Qp / Qs) using Doppler echocardiography or magnetic resonance angiography is more often used. The ratio of the volume of total pulmonary blood flow to systemic blood flow, i.e. the Qp/Qs ratio can serve as a criterion for the intensity of blood shunting through an intracardiac defect. The normal Qp/Qs ratio is 1:1. If there is a discharge of blood from the systemic circulation to the small one or vice versa, the volume of this discharge can be calculated using the formulas:
Shunt volume from left to right = Qp - Qs;
Shunt volume from right to left = Qs - Qp.
With cyanotic defects with hypovolemia of the small circle, the blood flow in the lungs decreases, and the Qp / Qs ratio is 2.0-2.5: 1. If the patient has a bilateral (left-right and right-left) discharge of the same magnitude, the ratio Qp/Qs can be equal to 1:1.
Hypoxemia in CHD is most often associated with the flow of venous blood into the left sections and the systemic circulation, i.e. with right-left reset. The discharge of blood from right to left can occur at different levels.
Thus, a discharge at the level of the veins of the systemic circulation occurs due to their abnormal confluence, for example, with a defect in the coronary sinus or when the superior vena cava empties into the left atrium. Right-to-left shunt at the level of the atria occurs with obstruction or insufficiency of the tricuspid valve. This occurs with atresia of the tricuspid valve or its stenosis and the hypoplasia of the right ventricle accompanying these defects, Ebstein's anomaly, and sometimes with perinatal asphyxia with ischemic damage to the papillary muscles of the tricuspid valve. In these cases, the pressure in the right atrium increases, and venous blood flows through it, through the oval window, or an atrial defect from right to left. The right-left shunt at the level of the right ventricle is observed in Fallot's tetrad, a two-chamber right ventricle, i.e. with defects with obstruction of the outflow tract of the right ventricle and VSD. Dumping from right to left at the level of the pulmonary arteries also occurs in individual patients - both in combination with Fallot's tetrad, and in isolation (with Alagil's syndrome, Williams' syndrome).
In heart defects with a unidirectional right-to-left shunt, cardiac output to the systemic circulation is not affected, but pulmonary blood flow is reduced as a result of right-to-left shunting. A complication of right-left shunting is hypoxemia and its consequences. Since the blood in the pulmonary veins is normally saturated with oxygen, O2 inhalations do not have a significant effect and only slightly increase the oxygen content in the blood due to its soluble fraction. With long-term hypoxemia, erythropoiesis increases compensatory (Er number > 5x1012/l) with a simultaneous increase in hemoglobin levels (Hb > 160-180 g/l). As a result, the content of oxyhemoglobin in the blood and hematocrit (Ht> 55%) increase. Prolonged severe hypoxemia in malformations with cyanosis is accompanied by such complications as secondary malabsorption and growth retardation, as well as hypoxic brain damage (pyramidal insufficiency, hypertensive-hydrocephalic syndrome, cognitive disorders, etc.).
Sometimes, due to iron deficiency, anemia is observed, which is manifested by a normal or low level of hemoglobin and hematocrit with an increased or normal number of red blood cells. Anemia is more common in infants, especially at 2–3 months of age, due to latent or overt iron deficiency. Despite an increased or normal number of red blood cells, hypochromia, microcytosis, and a decrease in serum iron are observed. In case of anemia, it is necessary to prescribe treatment with iron preparations and mandatory monitoring of the nutritional status (feeding with breast milk or adapted milk formulas). With prolonged hypoxemia and erythrocytosis, older children may develop thrombocytopenia and clotting disorders with subsequent bleeding, including after surgical interventions. Both polycythemia and anemia and thrombocytopenia threaten the development of strokes, especially in young children.
An increase in blood viscosity threatens thrombosis of the vessels of the internal organs, in the pools, primarily the cerebral, renal, pulmonary and mesenteric arteries. The risk of thrombosis increases in a situation of dehydration (with fever, in hot weather, with dyspeptic disorders). Another complication of heart defects with cyanosis are brain abscesses. They arise due to the fact that bacteria, which are normally neutralized in the vessels of the lungs, enter the right-left discharge directly into the vessels of the large circle, including the cerebral ones.
Heart failure with heart defects primarily occurs due to an overload of the heart chambers with an excess volume of blood (for example, with left-right shunts), an increase in vascular resistance in the pulmonary or systemic circulation, and a decrease in cardiac output due to obstruction of the outflow tract of the left ventricle. These situations are discussed below in the discussion of hemodynamic disorders resulting from each specific defect.
A typical complication of congenital heart defects is secondary bacterial endocarditis, which is associated primarily with defects with cyanosis, which requires mandatory prevention of this complication during medical procedures associated with potential bacteremia.
Ventricular septal defect(VSD) - CHD with a message between the right and left ventricles.
Code according to the international classification of diseases ICD-10:
- Q21.0
Causes
Etiology. Congenital malformations (isolated VSD, an integral part of the combined congenital heart disease, for example, tetralogy of Fallot, transposition of the great vessels, common arterial trunk, tricuspid valve atresia, etc.). There is evidence of autosomal dominant and recessive inheritance patterns. In 3.3% of cases, direct relatives of patients with VSD also have this defect. Rupture of the interventricular septum in trauma and MI.
Statistical data. VSD is 9-25% of all CHD. Detected in 15.7% of live births with CHD. As a complication of transmural MI - 1-3%. 6% of all VSDs and 25% of VSDs in infants are accompanied by patent ductus arteriosus, 5% of all VSDs by aortic coarctation, and 2% of congenital VSDs by aortic valve stenosis. In 1.7% of cases, the interventricular septum is absent, and this condition is characterized as the only ventricle of the heart. The male to female ratio is 1:1.
Pathogenesis. The degree of functional impairment depends on the amount of blood shedding and total pulmonary vascular resistance (OLVR). When resetting from left to right and the ratio of the pulmonary minute volume of blood flow to the systemic (Qp / Qs) is less than 1.5: 1, the pulmonary blood flow increases slightly, and there is no increase in TLSS. With large VSDs (Qp/Qs more than 2:1), pulmonary blood flow and OLSS increase significantly, and the pressures in the right and left ventricles are aligned. As the OLSS increases, it is possible to change the direction of blood discharge - it begins to occur from right to left. Without treatment, right ventricular and left ventricular failure and irreversible changes in the pulmonary vessels (Eisenmenger's syndrome) develop.
DMZHP options. Membranous VSDs (75%) are located in the upper part of the interventricular septum, under the aortic valve and the septal leaflet of the tricuspid valve, and often close spontaneously. Muscular VSDs (10%) are located in the muscular part of the interventricular septum, at a considerable distance from the valves and the conduction system, are multiple, fenestrated, and often close spontaneously. Supracrestal (VSD of the outflow tract of the right ventricle, 5%) are located above the supraventricular crest, often accompanied by aortic aortic valve insufficiency, do not close spontaneously. An open AV canal (10%) is found in the posterior part of the interventricular septum, near the place of attachment of the rings of the mitral and tricuspid valves, often occurs in Down syndrome, is combined with ASD of the ostium primum type and malformations of the leaflets and chords of the mitral and tricuspid valves, does not close spontaneously . Depending on the size of the VSD, small (Tolochinov-Roger disease) and large (more than 1 cm or half the diameter of the aortic orifice) defects are isolated.
Symptoms (signs)
Clinical picture
. Complaints:
. Objectively. Paleness of the skin. Harrison's furrows. Strengthening of the apex beat, trembling in the region of the left lower edge of the sternum. Pathological splitting of the II tone as a result of a lengthening of the right ventricular ejection period. Rough pansystolic murmur at the left lower edge of the sternum. With supracrestal VSD - diastolic murmur of aortic insufficiency.
Diagnostics
Instrumental diagnostics
. ECG: signs of hypertrophy and overload of the left sections, and in case of pulmonary hypertension - and right ones.
. Jugular phlebography: high-amplitude A waves (atrial contraction with a rigid right ventricle) and, sometimes, a V wave (tricuspid regurgitation).
. EchoCG.. Hypertrophy and dilatation of the left sections, and in case of pulmonary hypertension - also of the right.. Visualization of VSD in Doppler and B-mode.. Diagnosis of concomitant anomalies (valvular defects, coarctation of the aorta, etc.) .. Determine the systolic pressure in the right ventricle, the degree of blood flow and Qp/Qs .. Adults undergo transesophageal echocardiography.
. Chest x-ray.. With small VSD - a normal radiological picture .. Bulging of the arch of the left ventricle, increased pulmonary vascular pattern .. With pulmonary hypertension - bulging of the arch of the pulmonary artery, expansion and unstructured roots of the lungs with a sharp narrowing of the distal branches and depletion of the pulmonary vascular pattern.
. Radionuclide ventriculography: see Atrial septal defect.
. Cardiac catheterization. Indicated for suspected pulmonary hypertension, prior to open heart surgery and inconsistent clinical data. Calculate Qp/Qs.
. Left ventriculography, coronary angiography: imaging and quantification of shedding, diagnosis of CAD in the presence of symptoms or before surgery.
Medical treatment. With an asymptomatic course and normal pressure in the pulmonary artery (even with large defects), conservative treatment is possible up to 3-5 years of life. With stagnation in the pulmonary circulation - peripheral vasodilators (hydralazine or sodium nitroprusside), which reduce the discharge from left to right. With right ventricular failure - diuretics. Before and within 6 months after uncomplicated surgical correction of VSD - prevention of infective endocarditis.
Treatment
Surgery
Indications. With an asymptomatic course - if by 3-5 years of age there is no spontaneous closure of the defect, although the best results are achieved with surgical treatment at the age of up to 1 year. Heart failure or pulmonary hypertension in young children. In adults, the Qp/Qs ratio is 1.5 or more.
Contraindications: see Atrial septal defect.
Methods of surgical treatment. Palliative intervention - narrowing of the pulmonary trunk with a cuff, if necessary, an emergency operation is performed for children weighing less than 3 kg, with concomitant heart defects and little clinic experience in radical correction of the defect at an early age. With a traumatic defect in the area of the membranous part of the interatrial septum, the defect may be sutured. In other cases, the defect is repaired with a patch of autopericardium or synthetic materials. In post-infarction VSD, the defect is repaired with simultaneous coronary bypass grafting.
Specific postoperative complications: infective endocarditis, AV block, ventricular arrhythmias, VSD recanalization, tricuspid valve insufficiency.
Forecast. In 80% of patients with large VSD, spontaneous closure of the defect occurs within 1 month, in 90% at the age of up to 8 years, there are isolated cases of spontaneous closure of the VSD between the ages of 21 and 31 years. With small defects, life expectancy does not change significantly, but the risk of infective endocarditis increases (4%). In medium-sized VSD, heart failure usually develops in childhood, and severe pulmonary hypertension is rare. Large VSD without a pressure gradient between the ventricles in 10% of cases lead to the development of Eisenmenger's syndrome, most of these patients die in childhood or adolescence. Emergency surgery is necessary in 35% of children within 3 months after birth, 45% within 1 year. Maternal mortality during pregnancy and childbirth with Eisenmenger's syndrome exceeds 50%. With postinfarction VSD after 1 year, in the absence of surgical treatment, 7% of patients survive. Hospital mortality after narrowing of the pulmonary artery is 7-9%, 5-year survival rate is 80.7%, 10-year-old survival rate is 70.6%. Mortality in the surgical treatment of postinfarction VSD is 15-50%. Hospital mortality in case of closure of isolated congenital VSD with low OLVR is 2.5%, with high OLVR — less than 5.6%.
Abbreviations. Qp/Qs is the ratio of the pulmonary minute volume of blood flow to the systemic one. TRL is total pulmonary vascular resistance.
ICD-10. Q21.0 VSD
J. Boatman
Abbreviations
QP/QS - ratio of pulmonary to systemic blood flow
PLA - pressure in the pulmonary artery
VSD - ventricular septal defect
ASD - atrial septal defect
PH - pulmonary hypertension
PDA - open ductus arteriosus
Open ductus arteriosus
General information
In the fetus, the ductus arteriosus is a functioning vessel that connects the pulmonary
artery with the descending aorta, most often - just below the place of origin of the left
subclavian artery. High PVR, characteristic of the fetal circulation,
causes blood to flow from right to left (from the pulmonary artery to the aorta) through
arterial duct, as a result of which oxygen-poor blood from the pancreas bypasses
unexpanded lungs of the fetus, enters the descending aorta and goes to
placenta, where it is saturated with oxygen. After the birth of LSS, abruptly
decreases, resulting in a change in the direction of blood flow through
ductus arteriosus (from the aorta to the pulmonary artery).
The ductus arteriosus may remain open after birth, especially in preterm infants, with persistent hypoxemia, or with fetal rubella syndrome Clinical presentation Narrow PDA in infancy often goes unrecognized; may manifest in childhood or in adults with fatigue and shortness of breath.
A wide PDA often presents with symptoms of congestive HF (orthopnea, dyspnea on exertion, nocturnal attacks of cardiac asthma), which results from left-to-right shunting and chronic left-sided volume overload. Possible PH with the development of right ventricular failure (swelling of the cervical veins, ascites, enlarged liver, swelling of the legs). As PH progresses, a change in the direction of shunting is possible, which is manifested by isolated cyanosis of the legs, rapid fatigue of the legs during exercise, and paradoxical embolism Course and prognosis in the absence of treatment Narrow PDA generally does not affect life expectancy, although the risk of infective endocarditis increases.
Medium or wide PDA: Usually spontaneous closure does not occur. Over time, PH develops, congestive heart failure occurs, and the risk of infective endocarditis is high.
Life expectancy is reduced and averages 40 years. Infective endocarditis almost always occurs in a left-to-right shunt; the site of infection is the site of the pulmonary artery, located opposite the mouth of the duct and subjected to mechanical action of the blood stream. One of the manifestations of infective endocarditis is multiple embolism of the branches of the pulmonary artery.
Rare complication - dissection and rupture of aneurysms of the PDA Physical examination Appearance pulse palpation auscultation When reset from right to left (as a result of severe PH) - cyanosis of the legs and thickening of the distal phalanges of the toes ("drumsticks"), since from the pulmonary artery enters the descending aorta oxygen-poor blood. If the PDA connects to the aorta proximal to the origin of the left subclavian artery, cyanosis of the left arm is possible.
Peripheral vasodilatation that occurs during exercise leads to an increase in shunt from right to left, and therefore these symptoms become more distinct. With a large shunt from left to right, there is a jumping pulse and high pulse pressure.
In the absence of HF, the pulsation of the jugular veins is normal. The apex beat is increased.
Constant trembling in the I or II intercostal space on the left, increasing in systole Normal I and II heart sounds are often lost in constant "machine" noise.
Noise usually begins after tone I, reaches a maximum intensity to tone II and weakens during diastole. Best of all, the noise is heard in the II intercostal space on the left; the noise is high-frequency, widely radiating, including in the back.
As PH develops, the murmur disappears (first diastolic and then systolic components) as the peripheral vascular resistance and PVR equalize.
With a large reset from left to right - signs of overload of the left ventricle and the left atrium.
Overload of the right ventricle and the right atrium indicates a pronounced PH With a large reset - an increase in the left ventricle and left atrium, increased pulmonary vascular pattern, bulging of the ascending aorta and expansion of the proximal branches of the pulmonary artery. In PH, the RV increases. In a two-dimensional study, it is occasionally possible to visualize an enlarged ductus arteriosus.
Doppler studies (including color mapping) reveal a constant, occupying the entire systole and diastole, flow in the pulmonary artery trunk. Other signs include an increase in oxygen saturation (from the pancreas to the pulmonary artery) and a decrease in peripheral blood oxygen saturation (when shunting in both directions or from right to left). It is possible to identify other congenital malformations.
Sometimes it is possible to pass a catheter through the PDA (from the pulmonary artery to the descending aorta) Treatment medical surgical Prevention of infective endocarditis before and within 6 months after surgical correction (see p. 465).
HF is treated by conventional methods (see Chapter 9).
In infants, PDA closure is facilitated by prostaglandin synthesis inhibitors (particularly indomethacin) Elective surgical repair by ligation of the duct is safe (mortality
Preliminary results with endovascular methods for closing the PDA (double-umbrella) are promising, although these methods are still considered experimental Ventricular septal defects Background VSD is the most common congenital heart disease. VSDs occur with equal frequency in both sexes. In most cases, they are diagnosed in infancy due to a rough heart murmur.
In 25-40%, spontaneous closure of the VSD occurs, of which 90% - before the age of years.
The degree of functional impairment depends on the magnitude of the reset and the LSS. If there is left-to-right shunt, but QP/QS 2:1), pulmonary blood flow and PVR increase significantly; RV and LV pressures equalize. As the PVR increases, it is possible to change the direction of the discharge (from right to left), which is manifested by cyanosis, a symptom of "drumsticks";
the risk of paradoxical embolisms increases. If untreated, right ventricular and left ventricular failure and irreversible changes in the pulmonary vessels (Eisenmenger's syndrome) develop. Types Membraneous (75%): located in the upper part of the interventricular septum immediately below the aortic valve and septal cusp of the tricuspid valve.
They often close spontaneously.
Muscular (10%): located in the muscular part of the septum, at a considerable distance from the valves and the conduction system. Muscular VSDs are multiple, fenestrated, and often close spontaneously.
Supracrestal (VSD of the outflow tract of the pancreas, 5%): located above the supraventricular crest (the muscle bundle that separates the cavity of the pancreas from its outflow tract). Often accompanied by aortic insufficiency.
The AV canal does not spontaneously close (AV septal defect, VSD of the RV inflow tract, 10%):
found in the posterior part of the interventricular septum near the site of attachment of the rings of the mitral and tricuspid valves. Often seen in Down's syndrome. VSD is combined with ASD of the ostium primum type and malformations of the leaflets and chords of the mitral and tricuspid valves.
Does not spontaneously close Clinical picture The first manifestation is usually a rough heart murmur. Small VSDs are often asymptomatic and may go unrecognized. With large VSD, there is often a lag in physical development and frequent respiratory infections.
In those rare cases, when a patient with a large VSD survives to adolescence and adulthood, there are symptoms of right and left ventricular failure (dyspnea, swelling of the legs, orthopnea).
Eisenmenger's syndrome (irreversible PH due to left-to-right shunt) may present with dizziness, syncope, hemoptysis, brain abscesses, and chest pain Course and prognosis if untreated Small VSD: life expectancy does not change significantly, but risk of infective endocarditis increases.
Medium-sized VSD: HF usually develops in childhood; with spontaneous closure or reduction in size, improvement occurs. Severe PH is rare.
Large (no pressure gradient between the ventricles, or non-restrictive) VSDs:
in most cases are diagnosed at an early age, in 10% they lead to Eisenmenger's syndrome; most patients die in childhood or adolescence.
Maternal mortality during pregnancy and childbirth with Eisenmenger syndrome exceeds 50%; in 3.3% of cases, direct relatives of patients with VSD also have this defect. Physical examination appearance pulse palpation auscultation In HF, weakness, cachexia are observed; often find depressions in the lower part of the anterior chest wall, the so-called Harrison's furrows (arise due to chronic shortness of breath).
When dumping from right to left - cyanosis and "drumsticks" With small VSD, the pulse on the peripheral arteries is normal, the pulsation of the jugular veins is also not changed. In PH, there is swelling of the jugular veins, high-amplitude A waves (atrial contraction in a rigid RV) and, sometimes, a V wave (tricuspid regurgitation) on the jugular phlebogram Amplified apex beat. Trembling at the left lower edge of the sternum Rough holosystolic murmur at the left lower edge of the sternum. Pathological splitting of the II tone as a result of prolongation of the period of expulsion of the pancreas.
With supracrestal VSD, there is a diastolic murmur of aortic insufficiency Non-invasive ECG studies chest x-ray Echocardiography With a large reset from left to right: overload of the left atrium and LV, deviation of the electrical axis to the left.
With PH: RV overload, deviation of the electrical axis to the right. With small VSD: normal.
With a large reset from left to right: an increase in the left ventricle, an increase in the pulmonary vascular pattern due to an increase in pulmonary blood flow.
In PH: a pronounced increase in the trunk and proximal parts of the pulmonary artery with a sharp narrowing of the distal branches, depletion of the pulmonary vascular pattern.
Doppler studies (including color mapping) evaluate the magnitude and direction of the shunt, calculate PAP. Invasive studies Cardiac catheterization and coronary angiography are performed to confirm the diagnosis, measure PAP and rule out CAD (with appropriate symptoms and before surgery).
The magnitude of the discharge can be assessed qualitatively using left ventriculography and quantitatively by blood oxygen saturation in the pancreas (see p. 516; unlike ASD, instead of oxygen saturation of mixed venous blood, the value of the average saturation in the right atrium is used) PAP (even with large VSD) can be treated conservatively. If spontaneous closure does not occur by 3-5 years of age, surgical correction is indicated.
In pulmonary congestion, hydralazine (or sodium nitroprusside for emergency therapy) is used, which reduces TPVR to a greater extent than PVR, which leads to a decrease in left-to-right shunt and improvement. With right ventricular failure, diuretics are prescribed.
