Cardiomyopathies

De nition—> pathological conditions of the myocardium which are not due to hypertension, coronary artery
disease, valvular heart diseases , not due t congenital HD and related to conditions where the myocardium is
actively in amed
Defect within the myocardium

However, myocardial damage secondary to … not considered cardiomyopathy

1. BP
2. Coronary artery disease
3. Valvular heart disease
4. Congenital heart disease
5. Myocardium is in amed
—> all these conditions are not included in cardiomyopathies

Cardiomyopathies are due to

1. some intrinsic defect in the myocardium /
2. some disease that leads to primary abnormality within the myocardium which is not due to hypertension etc

Primarily cardiomyopathies are divided into 3 groups and these are

1. Dilated cardiomyopathy
2. Hypertrophic cardiomyopathy
3. Restrictive cardiomyopathy
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ECG interpretation: basic concepts
 Dilated cardiomyopathy Hypertrophic cardiomyopathy

- The LV is pathologically dilated - pathological hypertrophy of the - pathological in ltration in the

[sometimes even RV] myocardium myocardium. Due to this
- Congestive cardiomyopathy - This pathological hypertrophy is pathological in ltration the
- This pathologically dilated [balloon especially pronounced in the myocardium becomes rm —>
like ventricle cannot contract septum. Other part of the problem with relation [the ventricle
well]there is global hypokinesia, myocardium is only mildly cannot relax properly/ successfully
impairment in the movement of the hypertrophic BUT the inter- —> diastolic failure
myocardium/ impairment of the ventricular septum is grossly - Thickened myocardium due to
contractility of the myocardium hypertrophic, very severely in ltration —> fails to relax properly
- Global impairment in the contractility hypertrophic [the upper part of the —> it will not ll properly during
of the Left myocardium and Right septum especially] diastole —> so that incoming blood
ventricle - This pathological hypertrophy which can be accommodated and pumped
- Large but hypo kinetic heart/ failing is especially pronounced in the to the systemic circulation
heart upper part of the inter-ventricular - Myocardium in ltrated by Abnormal
- Systolic failure [both ventricles septum poses a signi cant protein , granulomas in ltrated by
become enlarged —> poor hemodynamic problem: iron = hemochrombtosis —>
contractile chambers —> leads to - The ventricle will contract strongly thickened in ltrated myocardium —>
systolic failure] [because there is more muscle ]—> diastolic failure
- Dilated cardiomyopathy is a hyperkinetic heart—> whenever the
condition where there is biventricular ventricle contracts the septum Size of the heart is almost normal but
failure with pathologically dilated becomes shorter —> when the the ventricle is rm [due to in ltration]
both chambers + global impairment ventricle becomes shorter the and it fails to relax properly [thick and
in contraction obstruction bulges in the cavity [in rm]
If there is only segmental impairment in every systole] [this obstruction - fails to relax during diastole
contraction —> maybe ischaemic heart dynamically during systole bulges - Fails to accommodate enough
disease into the cavity —> it will produce an preload
- clinically presents as systolic failure: obstruction to out ow - Fails to accommodate enough EDV
failure of contraction - Not normal hypertrophy as in aortic - This will lead to back pressure
stenosis [which is symmetrical, that
is equal in parts of the ventricle]
[equal and symmetrical in all parts of
the myocardium —> symmetrical
hypertrophic] vs hypertrophic
cardiomyopathy —> non
symmetrical hypertrophy
- Hypertrophic obstructive
cardiomyopathy / obstructive
cardiomyopathy
Abnormal hemodynamics due to
element of obstruction and abnormal
cavity [vs xed obstruction caused by
aortic stenosis]

100% genetic defect

1. 50% cases —> familial [AD]
2. 50% cases —> sporadic [new
mutation]
+++
- poorly contracting heart [hypo- - vigorously contracting heart strong In echocardiography —>
kinetic] heart]
- In Echocardiogram: u nd a very big - In Echocardiogram
heart with a very big cavity 1. Hypertrophy
[ contractility is poor throughout all 2. Asymmetrical hypertrophy
elements of the wall of the heart] - cavity of the ventricle is abnormal —>
banana shaped cavity
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+++Hypertrophic
Cause of unexplained death of young people especially young boys
Why ?
During exercise —> heart is becoming more dynamic —> if heart comes more dynamic —> obstruction becomes more
pronounced —> it becomes more di cult to eject blood —> aortic lling is less = pressure in the aorta will be decreased
[aorta is unde led]. At the top of that , because the subject is exercising —> arterioles in muscles will relax —> blood will be
stored in the peripheral system —> less blood to perfuse the heart
This may precipitate severe ischaemia and conduction abnormalities —> fatal cardiac arrhytmias [fatal cardiac
ventricular arrhytmias —> death ]
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 Dilated cardiomyopathy

Most common type of cardiomyopathy 90% of cases

Progressive cardiac dilatation with impaired contractility
- pathologically dilated ventricles
- Thin walls
- Di use impairment in the ability of the ventricles to contract
- Hypo kinetic ventricles
- Biventricular failure : both right + left ventricle fail to perform the systolic function
- Leads to systolic failure —>CCF
Symptoms [sigs of systemic and pulmonary congestion due to biventricular systolic failure]
1. Pulmonary edema [backward pressure due to systolic pressure]
2. Cough
3. Dyspnoea
4. PND
5. Orthopnoea
6. Bilateral crepitations in the bases of the lung
7. Hemoptysis
8. Weak pulse

9. Increased jugular venous pressure [pressure in the right ventricle high —> pressure in the atria high —> blood
from the jugular system cannot drain well in the superior vena cava]
10. Hepatomegaly [hepatic vein cannot drain into the inferior vena cava [inferior vena cava cannot drain in the
right atrium too]
11. Systemic edema
12. Ascites
Features of RVF & LVF —> systemic and pulmonary congestion —> Congestive cardiac failure —> congestive
cardiomyopathy [both ventricles are hypo-kinetic ] [—> congestive cardiomyopathy —> a type of congestive
cardiac failure]

+ CCF = any type of biventricular failure whoah leads to pulmonary and systemic congestion. Dilated
cardiomyopathy is one cause of congestive cardiac failure

Other cardiomyopathies do not produce CCF [from the very beginning]

+ Over lling of over lled dilated failure —> S3 [diastolic sound] [produced when an over lled ventricle is rapidly
lled ]
+ Ventricular dilation —> brous ring will stretch out [overstretching of the mortal ring—> mitral annulus
overstretch —> loss of coaptation during systole —> functional mitral valve regurgitation—> murmurs +
functional tricuspid valve regurgitation [these develop at very late stages] ]
+ Formation of thrombi [because of abnormal blood ow due to dilated ventricle —> stagnation of blood —>
thrombi formation [can led to pulmonary embolism or systemic embolism—> give anticoagulants

Etiology
mnemonic —> ABCCCD HP
1. Alcohol
2. Beri beri —> vitamin B 12 deficiency
3. Coxsackie virus
4. Cocaine [can also lead rot severe coronary artery vasospasm and precipitate MI in young adults]
5. Chagas disease
6. Doxorubacin[cancer drug]
7. Hemochromoatosis —> iron overload —> tissue damage —> restrictive or dilated cardiopathy [can damage
also the pancreases —> diabetes or the liver and cause cirrhosis]
8. Peripartum dilated cardiopathy or after pregnancy [a few weeks after]
+ most cases = idiopathic
+ Genetic factors
+ Certain mutations lead to mutant proteins in the myocardium
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 + Dystrophin: transmembrane Protein that stabilises the intracellular sarcomeres by attaching them
through the cell membrane to the basement membrane —> stabilizing the contradiction
+ In some types of dilated cardiomyopathies the dystrophin is abnormal —> intracellular force
generating operators=sarcomeres cannot be stabilised to the cell membrane and ECM proteins —>
systolic failure —> ventricle cannot pump the blood it receives —> increase in EDV —> volume
overload —> dilated cardiomyopathy

-Since contractile function is impaired —> the tension generated in the

ventricles is reduced —> decrease in pressure
-Systolic failure —> increase EDV —> volume overload —> dilation of the
ventricle —> increase in the Radius of the chamber —> further decrease in
Pressure
-—> drastic fall in the pressure generated —> myocardial systemic cannot
generate good pressure to push the blood and maintain the CO
[functional defect in force generating mechanisms]

Different pts with dilated cardiomyopathy have different underlying defect

Some defects in dystrophin
Some others have mutant genes which make the enzyme for oxidative phosphorylation —> not enough energy —
> not good contractility [structural defect in force generating mechanisms]

Myocardial cells can use fatty acids as an energy fuel. Sometimes the enzymes which are concerned with the
utility/ breakdown of fatty acids are mutated —> those enzymes [concerned with beta oxidation of fatty acids are
mutated] —> no energy —> no force generated —> systolic failure

Mutations leading to Problems with force generation or problems with force transmission

30 % of cases of dilated cardiomyopathy are due to genetic influences

When the myocardium becomes abnormally dilated —> overstrechi got the conduction system —> abnormalities
with conduction —> arrhytmias

Complications
1. Cardiac arrhythmias
2. Thromboembolism
3. Function regurgitation in mitral and tricuspid system

Treatment
Reduce the preload
Arteriodilators
Venodilators
Hypertrophic cardiomyopathy

- Unusual type of myocardial hypertrophy that is not secondary to aortic stenosis or systemic hypertension
- Almost 100% due to some underlying genetic mutation
- Asymmetric hypertrophy : a pathological hypertrophy in the superior part of the inter-ventricular septum — >
cavity of the LV no more oval or circular but banana shaped
- Abnormal hypertrophy produces dynamic obstruction to the Lv outflow system. HOW?
- During contraction of the ventricle —> the septum gets shorter and thicker and bulges into the cavity of the
ventricle obstructing the section of blood into the aorta

Problem in the proteins of the sarcomere

The mutant protein- most common mutation
1. Heavy chain beta myosin [HCM] is mutant
2. Troponin or tropomyosin is mutant
3. But how to differentiate between dilated and hypertrophic cardiomyopathy ?
In dilated cardiomyopathy the problem was in either every generation or dystrophin was defected. BUT in
hypertrophic cardiomyopathy —> protein defects are within the sarcomeres : myosin ,actins or tropomyosin are
mutant —> sarcomeres cannot produce force [defective force generation] —> these pts have primarily defects in
sarcomere proteins —> impaired force generation —> contractility is abnormal
When force generation is impaired and contractility is abnormal —> these cells produce a lot of growth factors
[cells cannot produce as much force as required —> growth factors —> growth of myocardial cells —> leading to
hypertrophy
So the heart is
1. Thick wall
2. Heavy
3. Hyper-contractile

If u look at the free way thickness and septal thickness and u make a ration —> ST = 1,3 X FWT

What will u find under the microscope ?

Histologically we will see that
- bundles of myofibrils show disarray - disorganised myocytes
- Large myocytes with prominent nuclei + bundles are disorganised [hep hazard disarray bundles of myocytes,
myocyte are abnormally arranged or within an individual cardiac myocytes sarcomeres are abnormally arranged
1. Disarray of bundle of myocytes
2. Disarray of individual myocytes
3. Disarray of sarcomere arrangement within the myocyte
4. Interstitial fibrosis

What is the major hemodynamic problem ?

At the peak of systole this bulge becomes maximum and at the peak of systole the anterior leaflet of mitral valve
may attach there and there will be some small degree of regurgitation [due to small stream of blood being ejected]
 Due to this, during every systole, mitral valve anterior leaflet hits on the dynamic obstruction and that will lead to a
change of both ..[due to damage ion both structures]
1. Anterior leaflet will become thickened
2. Hypertrophic point will develop a plague

CO cannot be maintained due to obstruction

Hyper dynamic and jerky pulse
Because ventricle is straining too much to push the blood out against the dynamic obstruction —> force
generation is more and bold flow to the coronary vessels is less —> this precipitated ischaemia —> many develop
angina pain
Sometimes during vigorous exercise these pts may develop fatal tachyarrhythmia

HCM —> most common cause of sudden cardiac death in young adults during activity/ exercising

1. Anginal pain
2. High risk of tachyarrhythmia
3. Diastolic failure component —> because the heart is thick and cannot relax well —> pulmonary congestion
develops —> exertional dyspnoea
4. Due to outflow obstruction —> special type of murmur: harsh systolic murmur
SOS —> similar murmur is produced during aortic stenosis [clinical symptoms are generally the same between he
2 diseases but in aortic stenosis new have symmetrical hypertrophy, caused by RF not by the myocardium itself
due to genetic disease [in AS hypertrophy is secondary to to the stenosis]

How do u differentiate between the AS murmur and HOCM murmur ?

AS murmur - Whenever there is more blood coming to the ventricle [increase in VR—> preload —> EDV] —>
—> xed whenever there is more blood to be pumped —> LV will contract more/stronger in aortic stenosis —>
obstruction since it contracts stronger —> more harsh and prolonged will the murmur become = the murmur
produced by aortic stenosis
- All these conditions that increase the left ventricular lling will increase the murmur
- If the ventricle is over lled —> it will have to eject a greater volume of blood against a stenotic valve
—> produce increased intensity murmur

When there is increased LV Filling that is EDV —> increased murmur of AS [due to stronger
contraction for a longer time against the stenotic blood
Less EDV —> murmur will be decreased

Which conditions increase the EDV?

1. Venoconstriction —> Increased VR —> increased EDV —> increase in the intensity of the murmur
2. When lying down: if u lay down there is more VR to the heart —> murmur will increase
3. If u go into squatting position —> veins are squeezed —> increase in VR
When will the intensity and duration of the murmur of AS decreased —> when VR is decreased
1. Vasodilation
2. From lying down position if u suddenly stand up —> VR reduced
SO
EDV INCREASED —> AS murmur increased
EDV DECREASED —> AS murmur decreased

HODC murmur If the ventricle is unde led —> then nearer —> louder murmur
—> dynamic If cavity over lled [cavity stretched out—> separated —> less murmur
obstruction Points of obstruction come nearer

EDV increased —> MURMUR decreased

EDV decreased —> murmur increased

If u suspect that your pt has either HOCM / AS instruct them to squat

If the murmur increased —> AS
If he murmur decreased —> HOCM
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- Both of them harsh ejection systolic murmur
- Both are due to outflow obstruction to the let ventricle but in AS —> fixed obstruction —>/ in HOCM —>
dynamic obstruction

These pts can go into fatal arrhytmias and infective endocarditis + Left atrial fibrillation risk
Complications
1. Fatal arrhythmias
2. IE [due to damage of the obstruction points]
3. Left atrial fibrillation [stiffened ventricle —> atrium will undergo hypertrophy —> eventually dilation and
arrhythmias
4. Risk of thrombosis increases
5. Left ventricular failure

6. S4 —>whenever the left atrium contracts very strongly against a stiffened ventricle —> it produces a S4 sound
[S3 in dilated hearts [in dilated ventricle when rapid ventricular filling occurs] while S 4 in hypertrophies hearts]
[when atrial forcefully contract against a stiffened ventricle —> S4]

S4 will exist as long as sinus rhythm exist —> in AF —> S4 disappears

Whenever Atrial fibrillation starts —> atria have no mechanical activity because electrical activity is so fast that the
mechanical activity cannot follow —> S4 disappears

Treatment
U want to make this heart slow or fast ?
During tachycardia the heart becomes more dynamic —> here is less blood within it
We treat this condition with beta blockers —> slow the heart down —> longer time for the heart to fill —> if very
well filled obstructed element become less [in pt with tachycardia EDV is less BUT in a pt with bradycardia EDV is
increased]
WE =try to increase EDV [that is why we use beta blockers]
2. Surgical excision of the hypertrophic myocardium
3. Through a catheter they put alcohol [they inject alcohol] —> irritates the area and produced localised MI —>
infected area will heal with fibrosis and obstruction will reduce [fibrotic tissue occupies less volume thus
decreasing the obstruction]
Restrictive cardiomyopathy

Type of myocardial myopathy in which filling goof the ventricle is restrictive

Remember that the ventricles have 2 functions
1. Diastolic function —> related with ventricular filling —> ventricle should relax enough so that it could fill
adequately
2. Systolic function —> to maintain SV , CO
Those disease in which the ventricle cannot relax during diastole —> heart is undergoing diastolic failure
In some conditions the ventricle can relax well and it can receive the blood well BUT contracts poorly —> there is
systolic failure

When heart fails to relax properly —> diastolic failure if it cannot contract properly —> systolic failure

RCM —> Myocardium becomes firm and dopes not relax well —> diastolic failure
Normal size of the ventricle but firm
Since the heart does not relax people the CO will not be maintained —> increase in LV filling pressure —> back
pressure [the pulmonary system cannot drain to the left heart. Id diastolic failure in right heart —> systemic
congestion

Causes
1. Idiopathic Cause is not known

2. Post radiation brosis If someone has mediastinal tumors or lung tumors and we give radiation for that —> that
radiation may injure the myocardium as well —> myocardium undergoes brotic replacement
—> if a lot of brosis after the radiation —> brotic mass cannot relax well —> RCM

3. Amyloidosis Extracellular deposits along the basement membranes

Interstitial deposition of amyloid = a special type of protein—> Transthyretin [ a protein in the
plasma which transfers the thyroid hormone and the retinoid acid —> in some pts this
transthyretin becomes modi ed and gets deposited between the myocardial cells

This protein is beta plated —> once this protein is deposited it is never removed. This is
because we lack the enzyme that digests it

All the proteolytic enzymes in our body break down a helical arrangement [a helically arranged
proteins] - we do not have any enzymes which break down the beta plated proteins

So any protein in our body which has undergone beta plating and deposits extracellularly —> is
called amyloid [amyloid is any protein in the protein which has a beta plated conformation —>
when this amyloid material deposits [always extracellularly] in some tissue —> compresses the
cells leading to degeneration of cells + amyloid also deposited around the capillaries that feed
the tissues =compression of the capillaries leads to ischaemic changes

So , amyloid is any protein in our body which has undergone beta plating thus becoming
resistant to degradation —> leading to progressive accumulation —> thus producing tissue
dysfunction
When amyloid is deposited I the heart —> heart hardened —> cannot relax well [all the
myocardial interstitium is in ltrated with amyloid

4. Sarcoidosis Multi-systemic granulomatous disease —> there is some immunological reaction in the body
and multi granulomas form in multiple tissues of the body

What are granulomas —> a collection of epitheliod cells [modi ed macrophages] surrounded
by rim of lymphocytes [giant cells might as well be present]
If thousands of granulomas in the heart —> heart will become harder and from —> cannot relax
—> cannot ll well —> restriction to lling —> failure of diastolic function

5. Glycogen storage These are inherited disorders in which certain enzymes that break down the glycogen are
diseases dysfunctional —> if those enzymes which can break down glycogen in the myocardial cell are
defective —> the glycogen will keep on accumulating in the myocardial cell —> the myocardial
cell become a bag of glycogen —> cannot relax well
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 6. In ltration of the The heart generally is not a very famous place for secondary metastasis but still ins some pts
myocardium by the myocardium might as well be in ltrated by a lot of secondary malignancies
metastasis —> metastatic growths in the myocardium

Naturally, if there are a lot of metastasis within the myocardial tissue —> rm —> cannot relax
—> heart will undergo diastolic failure

Special conditions associated with Restrictive cardiomyopathy

1. Endomyocardial This is more common in Africa

Fibrosis - brotic patched start to for at the apex of the left/right heart and start moving upwards. It
might even involve the mitral valve or the tricuspid valve
Because there is a lot of brosis the brotic layer does not allow the myocardium to relax well
and there is restrictive dysfunction

The endocardium is abnormal [the brotic endocardium is abnormal] —> on this platelets will
tick and mural thrombi will form [mural thrombi = thrombi attached to any wall of the CVS]

2. Loe er’s How do we recognise WBCs [see screenshot]

endomyocarditis
In this pt there are a lot of circulating eosinophils [many of these pts have associations with
eosinophilic leukaemia [—> how do u de ne leukaemia: malignancy of hematopietic precursor
cells which usually originate from the bone morrow]

Eosinophils have a very special product in their granules —> eosinophilic basic protein = major
basic protein —> this is a very destructive protein that is concentrated in eosinophilic granules

When in this pts this eosinophils cells are circulating in the heart, they degranulate and attack
the heart [release the major basic protein on the endocardium ]

So these highly dangerous eosinophils which are very fragile are ready to release their toxins/
dangerous products —> when present in bury high numbers in the circulation —> when they
pass through the heart, on the myocardium they release their major basic protein and keep on
damaging the myocardium —> so there is chronic damage, continuous damage to the
endocardium [going deeper to the myocardium] —> so endocardium an myocardium become
in amed and eventually become brotic —> so we can say that the patient is having
endomyocarditis because not only the endocardium is injured but the underlying myocardium
are also damaged

In the blood we can nd a lot of eosinophils which are degranulated [granules are empty]

With that naturally , a lot of mural thrombi form there

So pt is having leukaemia with eosinophilic proliferation —> eosinophils get degranulated and
most probably attack the heart [release the major basic protein there] —> chronic and severe
injury to the endocardium and underlying myocardium leads rot brosis and restrictive changes
there —> RCM

Treatment —> endomyocardial stripping —> a special instrument removes the injured, necrotic,
brotic area + mural thrombi and this way the prognosis becomes better

3. Endocardial - this is a problem of the children around the age of 2

broelastosis - In these pts local or di use tissue is deposited in the endocardium and deeper myocardium
—> the chamber cannot relax well + a lot of them obi might form in the left ventricle
- Usually these pts have some other congenital anomaly in the heart as well
- If there is focal disease —> prognosis is good
- If there is di use disease —> bad prognosis
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Restrictive cardiomyopathy should be well differentiated from constrictive pericarditis
Constrictive pericarditis

IN CP around the heart the surrounding pericardium has undergone ,massive brosis —> and due to this massive brosis
it becomes a very thick scar and this scar shrinks and compresses the ventricles —> ventricles are compressed and
cannot dilate relax to accommodate the diastolic lling

So clinically many pts with contrive pericarditis and restrictive cardiomyopathy —> develop similar clinical features
As a good doctor u should be able to di erentiate which cases have CP and which RCM

One of the very good ways to check is echocardiography

Endomyocardial biopsy may be required diagnosis of RCM

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