PATHOLOGY LAB 2
CARDIOMYOPATHIES AND PERICARDIAL DISEASES
J.P. Veinot M.D. FRCPC
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This lab will consist of review and discussion of kodachrome slides with an instructor.
MYOCARDIAL DISEASE - CARDIOMYOPATHIES
1.The heart has several responses to
injury, independent of the cause of the damage. The most common include
dilatation of a chamber, hypertrophy of a chamber and fibrosis. Myocardial
infarcts would be an example of myocardial fibrosis. The regenerative
capability of the myocardium is limited.
The heart in the slide came from a 24
year old male patient with no other known medical problems. He presented with
shortness of breath. This heart in cross-section has dilated and hypertrophied
right and left ventricles. Normal
heart for comparison ; Dilatated
Hypertrophy of a heart chamber implies what?
Dilation of a heart chamber implies what?
What sort of pathophysiologic abnormalities and clinical signs and symptoms
would a patient with a heart like this manifest ?
Ischemic injury is a very common form of myocardial injury and could cause a
heart to have ventricular dilatation and/or hypertrophy. Ischemia may cause
infarcts that are visible with the naked eye or ischemia may cause many tiny
microinfarcts that can only be seen under the microscope. Both may cause
changes in the ventricle dimensions.
Other non-ischemic (and non-myocardial)
abnormalities of the heart can cause the ventricles to react this way. Name
refers to diseases that primarily affect the heart muscle - myocardial
disorders. Some of these are primary cardiomyopathies while
others have a secondary cause.
new definition defines a cardiomyopathy as a heterogenous group of diseases of
the myocardium associated with mechanical or electrical dysfunction that
usually (but not invariably) exhibit inappropriate ventricular hypertrophy or
dilation and are due to a variety of causes that frequently are genetic.
either confined to the heart or are part of generalized systemic disorders
often leading to cardiovascular death or progressive heart failure related
classification of primary cardiomyopathies includes:
ARVC, LV non-compaction, glycogen storage (PRKAG2, Danon), conduction defects,
mitochondial, ion channel (LQTS, Burgada, SQTS, CVPT, Asian SUNDS)
(myocarditis), stress (tako tsubu), tachycardia induced, infant diabetic
a practical basis, pathology groups them into 3 groups:
cardiomyopathy - abnormalities in systole, generally dilated chambers
cardiomyopathy - abnormalities in diastole, generally hypertrophied
cardiomyopathy - abnormalities in diastole, dilated atria usually
Molecular biology has shown us
that in many of these cases of primary dilated cardiomyopathy the abnormality
is with the CYTOSKELETON of the myocytes. Other research indicates there are
problems or susceptibility to FREE RADICAL myocyte damage or increased
APOPTOSIS of the myocytes. Many of these PRIMARY DILATED CARDIOMYOPATHIES are
It is important to remember that
coronary artery disease, valvular heart disease or systemic arterial
hypertension can produce secondary changes of dilation and hypertrophy of the
chambers. It is important to rule out these diseases before one diagnoses the
patient with a myocyte disorder.
3.This microscopic section shows another
form of myocardial injury. Myocardial
What is it?
This patient was an 18 year old male who died suddenly when playing
basketball. What is the pathogenesis of this form of myocardial damage?
4. This is a gross photograph of the
heart from which the last slide was taken, opened at autopsy. The heart has
many similarities to that of the last case of dilated cardiomyopathy. This
heart is dilated and flabby. The myocardium seems pale due to inflammation and
with myocarditis .
What abnormalities does this heart show?
Most myocarditis is either of unknown
cause or is related to viral infections.
may have a definite relationship with secondary dilated cardiomyopathy. In
many cases of myocarditis the patient will recover, but some go on to develop
a dilated cardiomyopathy. Also when one performs microscopy on hearts with
dilated cardiomypathy sometimes myocarditis is present. It is now thought that
the virus causes damage to the cytoskeleton of the myocyte and thus produces
5. This is a patient with chronic
systemic arterial hypertension. Hypertrophied
What is the abnormality shown?
What valvular lesion might result in a heart which looks similar to this? Valves
What would the functional effect of having a ventricle like this be?
6. Here is a heart cut in a slightly
different plane. Orient the structures seen. Hypertrophic
What is the major abnormality and where is it located?
This is a case of HYPERTROPHIC CARDIOMYOPATHY. This is usually a genetically
inherited disease in which the main abnormality is with ventricular diastolic
function. There are symmetrical and asymmetrical types. The asymmetrical type
can be associated with septal hypertrophy and with ventricular outflow
obstruction. This can cause syncope or light headed spells. Sudden death is
unfortunately not uncommon in this disorder. There also may be problems with
arrhythmias, and heart failure. Molecular biology has found that the disorder
is due to mutation in the CONTRACTILE and SARCOPLASMIC PROTEINS of the myocyte.
These include myosin, tropomyosin, and troponin. Multiple mutations are
described and they probably have a different prognosis.
What sort of pathophysiologic abnormalities would you expect such a patient to
What other processes could mimic this disorder, and would need to be ruled out
7. This is a case of amyloid involvement
of the heart - or AMYLOID HEART MUSCLE DISEASE. amyloid
is a type of protein which may be deposited preferentially in the myocardium,
for unknown reasons. Some cases are related to multiple myeloma (plasma cell
malignancy) while other types are post-inflammatory or genetic.
This sort of deposition makes the heart stiff and the pathophysiologic
consequence is described as RESTRICTIVE (instead of DILATED or HYPERTROPHIC).
What does this term 'restrictive' imply?
are PRIMARY RESTRICTIVE CARDIOMYOPATHIES. These
are not common in North America, but are seen more in the tropics. RESTRICTIVE
disorders have problems with diastolic function.
What sort of endocardial lesion might also produce a restrictive pattern?
8. This is the pericardial surface of a
The surface should be smooth, but instead is abnormal. How would you describe
it? What term do pathologists use to describe this? Pericarditis
This sort of reaction is the early stage of reaction to many injuries. List
some which might cause this change.
Often such an inflammatory reaction is accompanied by accumulation of fluid in
the pericardial space. What is such an accumulation called?
9. This is an example of TUBERCULOSIS
involving the pericardial cavity. TB
How would you describe the abnormality?
What other pathology does this patient's heart show?
10. This is the lateral chest x-ray of
the same patient.
What is the abnormality?
What sort of pathophysiologic effect might this have?
What name is applied to this functional defect?
11. This is another, but different way
the pericardium may be made stiff, and non-compliant.
What is the likely diagnosis? Pericardial
Often this same problem may be accompanied, instead, by a PERICARDIAL
EFFUSION. What might be a good way to make a definitive diagnosis of this
12. This is an example of the commonest
form of primary heart neoplasm. myxoma
What is a neoplasm?
What do we mean by 'primary'?
If we use the term 'secondary' neoplasm, what does this mean?
This neoplasm is a LEFT ATRIAL MYXOMA (a benign tumour). What might presenting
clinical symptoms be? Do benign tumours ever harm the patient?
13. This is an AORTIC DISSECTION. The
aorta has split apart along its length. In this disorder the aorta tears its
inner intimal surface and blood splits the aorta media into two layers. As the
blood flows, the tear and aorta split propagates and rips or tears the aorta
into 2 channels. The blood in the "false' lumen may compress the vessel
and cause ischemia. The blood may also rupture out the adventitia of the aorta
The slides show how the aortic media is
split into inner and outer halves where the blood has split the media layer.
They show how a 'FALSE LUMEN' is produced, and show the ENTRY TEAR which is
usually found somewhere in thoracic (often ascending) aorta. Entry
What conditions might predispose to a dissection?
What sort of effects or complications might occur after a dissection?
Some people call these 'dissecting aneurysms' but this is a bad term - why?
With which tests can one diagnose a dissection clinically?