Volume 04 Issue 06-2024
70
American Journal Of Biomedical Science & Pharmaceutical Innovation
(ISSN
–
2771-2753)
VOLUME
04
ISSUE
06
P
AGES
:
70-78
OCLC
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1121105677
Publisher:
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Servi
ABSTRACT
In hypertrophic cardiomyopathy, the walls of the ventricles of the heart continue with symmetric or asymmetric
myocardial hypertrophy. Morphologically, in hypertrophic cardiomyopathy, fibrotic foci are detected based on the
incorrect arrangement of myocardial muscle fibers, small coronary vessel syndrome, and myocardial hypertrophy.
KEYWORDS
Heart, cardiomyocyte, hypertrophy, dystrophy, myofibril.
INTRODUCTION
Cardiomyopathy is a primary damage to the
myocardium, characterized by inflammation, tumor,
specific cardiomegaly not related to ischemia,
worsening heart failure and arrhythmia. It is
considered an idiopathic (unknown origin) disease of
the myocardium, which is based on the development
of dystrophic and sclerotic changes in cardiomyocytes.
The following types of primary cardiomyopathy are
distinguished: dilated, hypertrophic, restrictive and
arrhythmogenic [32,62].
Hypertrophic cardiomyopathy is manifested by diffuse
hypertrophy of one or all parts of the heart, narrowing
of the ventricles. Hypertrophic cardiomyopathy is
actually an autosomal dominant disease and occurs
more often in men of all ages. In hypertrophic
cardiomyopathy, the ventricular wall continues with
symmetric or asymmetric hypertrophy of the
myocardium.
Morphologically,
in
hypertrophic
cardiomyopathy, fibrotic foci are found on the basis of
incorrect location of myocardial muscle fibers,
Research Article
CHARACTERISTICS OF PATHOMORPHOLOGICAL CHANGES IN
HYPERTROPHIC CARDIOMYOPATHY
Submission Date:
June 20, 2024,
Accepted Date:
June 25, 2024,
Published Date:
June 30, 2024
Crossref doi:
https://doi.org/10.37547/ajbspi/Volume04Issue06-10
Oripova Ozoda Olimovna
Samarkand State Medical University, Samarkand, Uzbekistan
Journal
Website:
https://theusajournals.
com/index.php/ajbspi
Copyright:
Original
content from this work
may be used under the
terms of the creative
commons
attributes
4.0 licence.
Volume 04 Issue 06-2024
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American Journal Of Biomedical Science & Pharmaceutical Innovation
(ISSN
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VOLUME
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ISSUE
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70-78
OCLC
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"syndrome of small coronary vessels", myocardial
hypertrophy.
The
outcome
of
hypertrophic
cardiomyopathy is often poor, leading to death from
heart failure [56,59,104].
The purpose of the research
: to clarify the specific
macro- and microscopic changes of the heart in
hypertrophic cardiomyopathy;
METHODS
We reviewed 5,642 reports from the RPAM autopsy
department during 2011-2020, and a total of 64 CMPs
were identified during this period, accounting for 1.13%
of all autopsies and 4.7% of cardiovascular diseases. 15
of the 64 identified cases were found to be
hypertrophic cardiomyopathy.
After macroscopic examination of the heart,
1.5x1.5x0.5 cm pieces taken from the walls of both
ventricles and both compartments were frozen in a 10%
solution of formalin in phosphate buffer for 48 hours,
then washed in running water for 3-4 hours and placed
in a series of alcohol batteries of increasing
concentration (80˚, 90˚, 96˚, 96˚, 100˚) and dehydrated
in chloroform, paraffin with added wax was poured,
and bricks were prepared. Histological sections 5-
6 μm
thick were taken from paraffin blocks and stained with
hematoxylin-eosin and van Gieson stain to identify
connective tissue fibers. Histological preparations
were studied in 10, 20, 40 lenses of a light microscope,
and pictures were taken from the necessary areas.
RESULTS
It was found that the macroscopic appearance of the
heart in hypertrophic cardiomyopathy consists of the
following specific changes. The main hypertrophy-like
changes in the appearance of the heart are observed in
the left ventricle, where the wall of the left ventricle is
thickened by an average of 35-45 mm, all the walls of
the left ventricle are thickened to different degrees,
the greatest thickening is in the interventricular wall.
As a result, it was determined that the condition of
obstruction appeared around the blood outlet of the
left ventricle of the heart. In 11 of all 15 studied cases,
the above-mentioned morphological changes and the
development of an asymmetric form of hypertrophic
KMP were found. In the rest, it was found that the
heart was symmetrical, that is, all areas of the left
ventricle were hypertrophied to the same extent. As a
characteristic sign of asymmetric hypertrophic KMP, it
was observed that the wall of the left ventricle was
mainly thickened in the back and the interventricular
space, and the difference in wall thickness was 1.2 cm
on average. Only in some cases (2 cases) was it found
that the right ventricle of the heart was hypertrophied,
the orifice of the pulmonary artery narrowed, and
hypertension of the pulmonary artery developed in
hypertrophic KMP.
In hypertrophic cardiomyopathy, the ventricular and
ventricular spaces have changed to different degrees,
in most cases, the left ventricle is dilated and
expanded, there are specific structural changes in the
mitral valve layers, i.e., they are stretched and
Volume 04 Issue 06-2024
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elongated, and their area is increased. In 25% to 65% of
cases, thickening of the endocardium is detected,
especially in the upper part of the ventricular septal
wall, in areas close to the aortic valve.
Microscopic
examination
showed
that
the
myocardium of almost all patients had a strong
hypertrophy of cardiomyocytes. In this case, as specific
microscopic changes, it is observed that the muscle
fibers are arranged randomly, that is, in the direction of
different vessels. It is determined that most of the
myocardial muscle fibers are located in a circle (Fig. 1),
characteristic tufts of different thickness have
appeared, and tumor foci have appeared in their cores.
Fibrous tissue is densely located between the muscle
bundles consisting of cardiomyocytes, and the fibrous
bundles are noticeably thick in one place, and relatively
thin dark hematoxylinous bundles appear in other
areas. Cardiomyocytes are hypertrophied due to the
thickening of both myofibrils and sarcoplasm, and their
nuclei are relatively small and irregular. In other areas
of the myocardium, it is determined that part of the
muscle fibers are located longitudinally, and the other
part is located transversely. It is observed that the
myofibrils of the cardiomyocytes of the longitudinally
located muscle fibers are thickened to different
degrees, the transverse extension lines are lost, and
the nuclei are pushed aside. It is determined that
transversely located muscle fibers have different
thicknesses, some of them are sharply thickened, their
borders are unclear, and they merge with each other.
Fibrous tissue and malformed blood vessels are found
at the junction of muscle fibers in different directions
(Fig. 2). It is determined that the fibers in the fibrous
tissue are irregularly arranged, of different
thicknesses, and blood vessels similar to random
cracks have appeared between them.
In asymmetric forms of hypertrophic KMP, the
following changes were detected when microscopic
examination of the upper part of the wall of the
interventricular space of the heart, that is, the part
adjacent to the mitral valve. In this area as well, it is
determined that the myocardial muscle fibers are
chaotically located, as we can see in the picture, thick
muscle bundles are visible in cross-section, their
sarcoplasm is swollen, and myofibrils are thinned and
sparsely located.
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Figure 1. Hypertrophic KMP. It is observed that the muscle fibers are arranged irregularly, and the
interstitium between them is swollen. Paint: G-E. Floor: 10x40.
Figure 2. Hypertrophic KMP. Sharply thickened muscle fibers are located both longitudinally and transversely,
between which fibrous tissue has appeared. Paint: G-E. Floor: 10x40.
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Figure 3. Hypertrophic KMP. The upper part of the interspinous wall, the muscle bundles are chaotically arranged,
and relatively thick fibrous tissue has appeared between them. Paint: G-E. Floor: 10x40.
Figure 4. Hypertrophic KMP. Sclerosis and thickening of the wall of the coronary arteries located in the myocardial
intramural. Paint: G-E. Floor: 10x20.
It is observed that other bundles of myocardium are
located longitudinally and form the outer part of the
wall of the interventricular space, and myofibrils of
cardiomyocytes are relatively dense and darkly stained,
but their histotopography is disturbed due to
thickening. Between the muscle bundles located in the
two indicated directions, it is determined that each
muscle fiber is separated from each other, dense
fibrous tissue has appeared between them (Fig. 3).
Fibrous tissue differs from muscle fibers in terms of its
coloring and composition, it is determined that its
fibers are densely and irregularly arranged, and its cells
are relatively numerous and disorderly.
In hypertrophic KMP, it is determined that there are
specific morphological changes in the intramural
coronary arteries of the heart myocardium. In this case,
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it is observed that the walls of almost all intramural
coronary arteries are sclerotized and thickened. The
larger the diameter of the artery, the more connective
tissue grows around it and is found to be sclerosed
(Figure 4). It is determined that the intima of these
arteries is uneven, the cells in it are hypertrophied and
hyperchromic, and the basal membrane is also
thickened. Smooth muscle cells are found to undergo
both hyperplasia and hypertrophy, and some muscle
cells are surrounded by fibrous tissue. Due to the
abundance of fibrous structures in the surrounding
connective tissue, it is determined that it is densely
wrapped around the vessel in the form of a ring, as a
result, the artery cavity is compressed and narrowed. It
is determined that the walls of relatively small arteries
and arterioles are thickened due to the growth of the
connective tissue, which has spread and penetrated
into the surrounding muscle tissue.
As another characteristic change of hypertrophic KMP,
thickening of the endocardium of the left ventricle,
growth of connective tissue, and sclerosing were
found in most cases. It is observed that the
endocardium of the endocardium is atrophied and
desquamated in some places, migrated, and in other
areas it is proliferated, increased and thickened. The
basement membrane beneath the endothelium is
found to have almost disappeared, disintegrated, and
merged with the surrounding newly formed
connective tissue. It is observed that the endocardium
is thickened in the section (Fig. 5), and even grows
towards the myocardium adjacent to it. It is
determined that the connective tissue fibers and cells
in the endocardium have undergone dystrophy and
dysregeneration and have changed morphologically.
Fibrous structures are determined to be shriveled and
fragmented due to strong swelling in some places,
relatively pale in color, in other places they are dense,
homogenized, and destroyed like fibroelastosis and
hyalinosis. It is found that the cellular composition of
the endocardial tissue is thinned, their nuclei are
deformed and hyperchromic. Myocardial muscle fibers
adjacent to the endocardium are fragmented,
separated into parts, and most of them are destroyed.
The destruction of muscle fibers is manifested by the
loss of the nucleus, the loss of cross-promoting lines in
myofibrils, their homogenization and myolysis.
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Figure 5. Hypertrophic KMP. Thickening of the endocardium, elastofibrosis and hyalinosis of connective tissue
fibers. Paint: G-E. Floor: 10x40.
Figure 6. Hypertrophic KMP. Fibromatosis and sclerosis of the endocardium, invasion into the myocardium. Paint:
G-E. Floor: 10x20.
Fibromatosis and sclerosis are found in the
myocardium of the heart in individual cases. It is
observed that the rough fibrous connective tissue
completely covers the endocardial layer and has grown
into the myocardium (Fig. 6). Fibrous tissue contains a
significant number of fibrous structures with a coarse
structure, and the intercellular substance has a fine-
grained coarse eosinophilic structure. Fibrous
structures are chaotically arranged, and in some areas
dark colored fibrous concretions with a dense and
coarse texture are found. It is observed that
connective tissue cells are significantly less than
fibrous structures, they are randomly located, the
cytoplasm of most of them is vacuolated and
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expanded. As a result of fibromatosis of the interstitial
tissue of the myocardium, it is determined that the
muscle bundles are torn, fragmented and separate
islands appear, and the cardiomyocytes in these islands
are destroyed and located in a disorderly manner.
It should be noted that in most cases of hypertrophic
KMP, the functional state of the mitral and aortic
valves is impaired. The morphological basis of these
functional
disorders
is
definitely
the
pathomorphological changes developed in the
myocardium and, in addition, the development of
sclerosis and fibromatosis in both the myocardium and
the endocardium. The reason is that due to the
development of fibromatosis in the endocardium, the
sclerosis process spreads to the layers of the valves,
causing it to be structurally damaged. In this case, the
microscopic examinations showed that the myocardial
tissue adjacent to the layers of the heart valves is
hypertrophied and thickened, and the connective
tissue that is part of the valves adjacent to it is fibrosed
and thickened. It is determined that the fibrous
structures in the fibrous tissue have multiplied and are
scattered in this place, on the one hand, they have
spread to the myocardium, and on the other hand, they
have deformed the surface of the plate. It is
determined that the connective tissue cells in the
fibrous tissue of the cap layer are relatively few, and
those that are present are vacuolated, hydropic
dystrophy, and are randomly located.
CONCLUSION
In most cases of hypertrophic KMP, an asymmetric
shape is developed, the wall of the left ventricle is
mostly thickened in different degrees, the left ventricle
is dilated in most cases, specific structural changes in
the layers of the mitral valve, i.e., they are stretched
and elongated, and their area is increased. In 25% to 65%
of cases, thickening of the endocardium is detected,
especially in the upper part of the ventricular septal
wall, in areas close to the aortic valve. Microscopically,
this hypertrophic KMP is a typical condition, that is, the
muscle fibers are located in a chaotic and chaotic
manner, the connective tissue grows between the
muscle bundles, the fibrous tissue develops, the
fibrous tissue often occupies the subendocardial area
and the endocardium thickens, the fibrous tissue
spreads to the valvular layers, as a result, it leads to a
functional violation of the valve. proved.
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