1. Prepared by the assistant of the Department of
Propedeutics of Childhood Diseases
Koishybaeva K.Zh.
Congenital heart defects
2. Врожденные пороки сердца
Congenital heart defects (CHD) are abnormalities in the structure
of the heart and large vessels that form during embryonic development
(embryopathy), resulting in hemodynamic disturbances, which can lead to
heart failure and dystrophic changes in the tissues of the body.
3. Three groups of factors are important in the
etiology of CHD.
1. Primary genetic factors. The inheritance of the defect can be due to
quantitative and structural chromosomal abnormalities or single gene
mutations.
2. Teratogenic factors of the external environment: intrauterine infections,
drugs, alcohol, contact with toxic substances, adverse environmental factors,
nutritional deficiencies in the mother in early pregnancy, the age of the
parents (mother is under 15 years old or over 35 years old, father is over 45
years old), diseases and conditions of the mother herself.
3. The interaction of genetic factors and adverse environmental factors.
4. Phases of the CHD flow
1. The primary adaptation phase is the adaptation of the child's body to the
existing hemodynamic disorders. The severity of clinical manifestations
directly depends on the degree of hemodynamic disorders.
2. 2. The phase of relative compensation - a temporary improvement in the
child's condition, due to a relatively stable hyperfunction of the heart and
formed myocardial hypertrophy. This phase begins after 2-3 years of life
of a child with CHD, if he did not die in the first phase of the disease, and
lasts up to 12-15 years.
3. 3. Phase of decompensation (terminal) - a sharp decrease in
compensatory capabilities, the development of dystrophic and
degenerative changes in the heart and body tissues.
6. Transposition of great vessels (TGV)
CHD, in which the aorta departs from the right ventricle, and
the pulmonary artery - from the left; while the atrioventricular
valves and ventricles of the heart are formed correctly.
Hemodynamics.
With TGA, the large and small circles of blood circulation are
completely separated and function in parallel. The minimum
adequate blood circulation depends only on the presence of
existing messages between both circles of blood circulation.
After birth, an increase in pressure in the aorta and a decrease in
it in the pulmonary artery leads to aorto-pulmonary discharge of
blood through a functioning arterial duct and an increase in
pulmonary blood flow. With an open foramen ovale, depending
on the phases of the heart, venous-arterial and arteriovenous
shunting takes place alternately, which helps to maintain a
minimum gas exchange.
7. Clinical picture
From birth, children with TGV have
severe diffuse cyanosis, which does
not stop with oxygen therapy,
shortness of breath, frequent
respiratory diseases, physical
retardation, polycythemia and
hyperhemoglobinemia. Severe
circulatory failure is formed already
from the first months of life and
proceeds according to the
biventricular type.
Pulmonary hypertension develops
rapidly. Sometimes severe
hypoxemic crises occur.
Physical data
The borders of the heart are
expanded in diameter (mainly due to
dilatation of the right ventricle) and,
less often, upward. Determine the
emphasis and splitting of the II tone
on the pulmonary artery. The gamut
of noise is varied and depends on the
nature of the existing compensating
communications and associated VPS.
8. Instrumental methods used to diagnose congenital heart defects
1. ECG
2. Plain chest x-ray
3. Echocardiography (transthoracic and transesophageal)
9. Diagnostics
Electrocardiography - the electrical axis of the heart is deflected to the
right. From the first month of life reveal signs of right heart hypertrophy. In
the future, signs of left ventricular hypertrophy may appear.
Echocardiography- allows you to establish the spatial location of the aorta
and pulmonary artery, their relationship to the ventricles and associated
defects. In the longitudinal section, the parallel orientation of the excretory
tracts of both ventricles and both great vessels is visualized, while the
pulmonary artery does not bend around the aorta and departs from the left
ventricle. In cross-section, the aorta is located in front and on the right (D-
transposition) or in front and on the left (L-transposition), and the
pulmonary artery is in the back.
X-ray- characteristic features are: increased pulmonary vascular pattern of
the arterial type; the shape of the shadow of the heart resembles an egg
lying on its side (in the later stages, the shadow of the heart is spherical); a
narrow vascular bundle in a direct projection and an expanded one in a
lateral projection.
12. Isolated pulmonary stenosis (IPS)
Isolated stenosis of the pulmonary artery —is a congenital
anomaly characterized by stenosis of the outflow of blood from
the right ventricle into the pulmonary circulation.
Hemodynamics
The presence of an obstacle to the free outflow of blood from
the right ventricle and the formation of a high pressure gradient
between it and the pulmonary artery lead to an increase in the
end-diastolic pressure in the right ventricle, and then in the right
atrium. Hypertrophy and dilatation of the right heart occurs.
The blood flow in the pulmonary circulation decreases. With a
defect in the interatrial septum or an open foramen ovale, a
venous-arterial blood discharge occurs.
13. Clinical picture
With moderate IPS, clinical symptoms
may be absent. With severe stenosis,
pallor of the skin, shortness of breath
during exertion, increased fatigue, chest
pain due to the relative deficiency of
coronary blood flow occur. At school
age, children may moderately lag behind
in physical development. Sometimes a
centrally located heart hump forms.
Congestive heart failure is not typical
for this defect and develops only in
children with critical stenosis. When
pulmonary artery stenosis is combined
with an atrial septal defect or an open
foramen ovale, cyanosis may appear, the
shade of which (from crimson to dark
blue) is due to the size of the shunt and
the severity of the stenosis.
• Physical data
With pronounced IPS, systolic tremors are
determined in the second or third intercostal
spaces to the left of the sternum and
epigastric pulsation of the heart. The
borders of the heart are moderately enlarged
in diameter due to the right ventricle. The
pulmonary component of the II tone is
weakened. A characteristic symptom is a
rough systolic ejection murmur in the
projection of the pulmonary artery valve,
radiating to the left clavicle, to the vessels
of the neck and to the interscapular space.
• Sometimes you can hear the click of the
opening of the pulmonary valve.
14. Diagnostics
Electrocardiography- - reveals a deviation of the electrical
axis of the heart to the right, signs of hypertrophy of the
right heart (high-amplitude R wave in lead V1) and
metabolic disorders of varying severity.
Echocardiography- visualize the narrowing of the
pulmonary artery at the subvalvular or valve levels.
Determine the presence of high-speed turbulent blood
flow through the pulmonary valve and signs of overload
in the right heart.
X-ray- it is noted that the pulmonary pattern is depleted, the
heart is enlarged due to the right sections, and the pulmonary
artery swells due to poststenotic expansion.
15. Differential diagnosis
IPS is differentiated with atrial septal defect, partial
abnormal drainage of pulmonary veins, Fallot's
tetrad.
16. Coarctation of the aorta (CoA)
Coarctation of the aorta —congenital narrowing or complete break of the aorta in the
area of its arch, isthmus, lower thoracic or abdominal regions. In the overwhelming
majority of cases (more than 90%), the CoA is localized in a "typical" place - in the
area of the aortic isthmus.
Hemodynamics
With pronounced isolated CA, excessive hemodynamic load falls on the left ventricle
of the heart, which leads to its hypertrophy, sometimes with impaired coronary blood
flow. Proximal to the narrowing site (ascending aorta, aortic arch, carotid arteries and
vessels of the head, subclavian arteries and vessels of the shoulder girdle) arterial
hypertension occurs; distal to the site of constriction (descending aorta and vessels of
the lower half of the body) - arterial hypotension and decreased blood flow.
The compensating mechanism is the development of collateral circulation. When the
postductal type of CoA is combined with PDA, severe pulmonary hypertension is
rapidly formed due to a significant discharge of blood from the aorta into the
pulmonary artery. With the preductal type of CoA and PDA, the direction of blood
discharge can be different and depends on the difference in pressure in the aorta and
pulmonary artery.
17. Clinical picture
• With the "infantile" type of CoA (more often preductal
CoA with concomitant PDA or other CHD and weak
development of collateral circulation), from the first
weeks of life in children, signs of heart failure are noted
- increased fatigue, anxiety, pallor of the skin,
sometimes perioral or acrocyanosis, shortness of breath,
cough, wheezing in the lungs. Severe circulatory failure
develops, refractory to therapy and often leading to
early deaths. With the "adult" type of coronary artery
(more often, an isolated postductal coronary artery with
a good development of collateral circulation), the
adaptation period is easier, and the diagnosis itself is
often made only at school age due to the presence of
arterial hypertension and a complex of corresponding
complaints (headaches, dizziness, nosebleeds, etc.)
etc.). In this case, it is possible to identify a
disproportion in the development of the child - weak, in
comparison with the upper half of the body,
development of the muscles of the lower extremities
(pain and weakness in the legs when walking, etc.).
Against the background of physical activity, cardiac
arrhythmias and anginal pain may occur due to relative
coronary insufficiency.
• Physical data
In CoA, a characteristic feature is arterial
hypertension in the limbs, the blood supply of which
is provided by the vessels extending from the aorta in
front of the site of its narrowing, and arterial
hypotension in the limbs, which are supplied with
blood from the poststenotic parts of the aorta. In most
cases, the blood pressure in the upper extremities is
higher (or equal to) the blood pressure in the lower
extremities.
The apical impulse is usually enhanced and displaced
to the left. The borders of the heart are moderately
expanded to the left. The auscultatory picture is
varied. Reveal the accent of the II tone on the aorta. In
the second to fifth intercostal spaces along the left
edge of the sternum, a coarse systolic murmur can be
determined, radiating to the apex and base of the
heart, as well as to the vessels of the neck. More often
the noise is heard on the back between the left
shoulder blade and the spine. One-third of patients
have a diastolic murmur of aortic valve insufficiency.
18. Diagnostics
Electrocardiography - the electrical axis of the heart is moderately
deviated to the left. Characterized by signs of isolated left ventricular
hypertrophy and high T waves in the left chest leads.
Echocardiography - from the suprasternal approach, the narrowing
of the aorta is visualized. Doppler cardiography detects post-stenotic
accelerated turbulent blood flow and calculates the pressure gradient at
the level of stenosis.
X-ray - record an increase in the left heart, "usury" along the lower
edge of the 3rd-8th pairs of ribs, behind on both sides. The vascular
bundle bulges out along the right contour due to the expansion of the
ascending aorta.
19. Differential diagnosis
CоA is differentiated from arterial hypertension of a different etiology,
NCD, patent ductus arteriosus, ventricular septal defect, aortic
defects, endocardial fibroelastosis.
