Chapter 11: Complete lecture Flashcards
What is myocarditis?
Inflammation of the heart: infectious or non-infectious cause
What is (in 99% of the cases) the cause of myocarditis? (bacteria/virus/parasites)
Virus!
What can lymphocytic myocarditis cause?
- arrhythmia
- vasospasm (contraction of blood vessels -> myocardial infarction)
- heart failure (because of interleukins)
Is the amount of lymphocyts increased or decreased in patients of myocarditis?
Mostly increased (but some have no difference)
What ages does myocarditis mostly occur?
All ages! (so also young ones)
How can young patients have a myocardial infarction?
Because of myocarditis (vasospasm)
Do interleukins have a positive or negative effect on the heart muscle?
Negative! The contractility is reduced
True/false: there is no extensive cell death of cardiomyocytes during myocarditis
True, except for fulminant myocarditis
Are there more lymphocytes or more macrophages after a couple of days (viral myocarditis)?
More lymphocytes, this can be found up to 14days after the infection (this is from his study with mice/unpublished results, p34)
Fungi or bacteria can also be the cause of myocarditis, then there are no lymphocytes (primarily) found, but other cells. Which?
Neutrophilic granulocytes
We saw earlier that an acute myocardial infarction also causes neutrophilic granulocytes. So how can a fungi/bacterial myocarditis be distinguished from an acute myocardial infarction?
(fungi/bacterial) Myocarditis shows an aggregation of neutrophilic granulocytes Acute myocardial infarction shows an diffuse increase of neutrophilic granulocytes (i watched this about a 100x but he doesn’t say more than this / i don’t understand sorry)
What is myocytolysis
Cell death of myocardicytes
If you see increased eosinophilic granulocytes without myocytolysis, what can be the underlying cause of this?
Parasites (infectious) or drug induced (so it can be infectious/non-infectious)
If you see increased eosinophilic granulocytes with myocytolysis, what can be the underlying cause of this?
Hypereosinophilic syndrome (increased eosinophils in the blood)
What is a granuloma?
Aggregation of macrophages and/or giant cells
Myocarditis can be because of granuloma’s. What are diseases associated with this? (3 answers)
- Tuberculosis
- Sarcoidosis (no necrosis of cardiomyocytes)
- Giant cell myocarditis (limited granuloma’s; extensive necrosis of cardiomyocytes)
How is non-infectious myocarditis also called?
Stress-myocarditis
In stress-myocarditis/non-infectious myocarditis there is a diffuse increase of….
neutrophilic granulocytes, lymphocytes, macrophages
What types/part of the heart wall are damaged in stress-myocarditis/non-infectious myocarditis?
Both endo- and myocardium!!!
What can be the causes of stress-myocarditis/non-infectious myocarditis?
- feochromocytoma (tumour adrenal glands)
- brain injury
- lungemboli
- sepsis
A thrombus in the left ventricle causes a risk for…
Brain infarction
A thrombus in the right ventricle causes a risk for…
Lung emboli
So, to summarize, what can be causes of myocarditis?
- Inflammation of the heart: infectious or non-infectious (lung emboli/ brain injury / sepsis)
- In infectious myocarditis the predominant inflammatory cell points to the cause:
- lymphocytes: virus
- neutrophilic granulocytes: fungi or bacteria
- eosinophilic granulocytes: parasites
- aggregates of macrophages: tuberculosis
In case granuloma’s with giant cells are found in the heart with an infectious myocarditis, this is caused by: a: a viral infection b: a bacterial infection c: an infection with parasites d: tuberculosis
d: tuberculosis
What is cardiomyopathy?
Disease of the heart muscle
What are the four ways cardiomyopathy can present?
- Hypertrophic
- Dilated
- Restrictive
- Arrhythmogenic right ventricular
First we discuss hypertrophic cardiomyopathy. What changes on macroscopic level can be seen?
Increase and asymmetry of the heart wall
What are microscopic changes that can be seen during hypertrophic cardiomyopathy
Disarray of myofibrils and disarray of cardiomyocytes (-> ‘whorls)
How do whorls have a negative impact on the contractility?
Like the name suggests, they are whorls/not aligned, therefore if you would ask yourself in what direction a signal would go, you would not be able to answer it! (see p44/google, it will make sense)
What is the cause of hypertrophic cardiomyopathy?
Genetic: mutations in genes coding for sarcomeres (=contractility unit)
Onto the next part, dilated cardiomyopathy: how can this be seen macroscopically?
There is dilation of both the left, and right ventricle
How can dilated cardiomyopathy be seen microscopically?
Increase of fat tissue and fibrosis
Fill in: Heart failure is related to a *decrease/increase/no difference* of cardiomyocytes in hypertrophic cardiomyopathy. Heart failure is related to a *decrease/increase/no difference* of cardiomyocytes in dilated cardiomyopathy.
no difference, and loss respectively
What can also be a result of dilated cardiomyopathy (next to heart failure)?
Arrhythmia
What are the causes of dilated cardiomyopathy?
- Genetic: in case a CMP is related to a genetic cause: it is suggested that patients develop the fenotype of a CMP subsequent to an event (infarction or myocarditis: also for HCMP and ACMP)
- Alcoholic Cardiomyopathy
- Viral myocarditis
- After pregnancy
- Idiopathic= no clear cause
Alcoholic (dilated) cardiomyopathy shows a distinct macroscopic and microscopic view. Explain
Macroscopic: dilated and fatty (!) changed (mostly) left ventricle (but also right ventricle) Microscopic: cardiomyocytes have decreased density of myofibrils (!) and more liquid (fat inclusion)`
3rd cardiomyopathy was the restrictive cardiomyopathy. What is this, generally, caused by?
Increase of a ‘compound’ in the heart (such as glycogen, amyloid, iron)
How does amyloid impact cardiomyocytes (in restrictive cardiomyopathy)?
- Amyloid causes a decrease in cardiomyocytes
- Amyloid can be within cardiomyocytes (causing loss of myofibrils)
- Amyloid can be between cardiomyocytes
- Amyloid can be in blood vessels (both small capillaries and larger ones!)
What does amyloid within and/or in between cardiomyoctes cause?
Inhibition of heart function
What does amyloid in blood vessels cause?
Myocardial infaction
Glycogen can also cause restrictive cardiomyopathies, how?
They form vacuoles with glycogen, disrupting myofibrils
Next to glycogen, and amyloid, what else can cause restrictive cardiomyopathies?
Hemosiderosis (iron)
So, storage of glycogen and iron results in:
Less myofibrils and thus a decrease of heart function
What does ARVC stand for?
Arrhythmogenic right ventricular cardiomyopathy (the fourth! of cardiomyopathies) (almost theree)
What is seen in arrhythmogenic cardiomyopathy (macroscopically/microscopically)?
Macroscopically: Wall thinning of the right ventricle (fatty chagnes myocardium) Microscopically: fatty changes, with/without fibrosis
Does ARVC have a genetic cause?
Not per definition
So how can the difference be seen of alcoholic dilated and arrhythmogenic cardiomopathy be seen?
Alcoholic: left ventricle (mostly) Arrhythmogenic: right ventricle (mostly)
Sooo, to summarize it all, what are the four types of cardiomyopathy and their characteristics?
- Hypertrophic: asymmetric thickening of 1 wall of the heart (mostly septum)
- Dilated: dilatation of the ventricles
- Arrhythmogenic: thinning and fatty changes of the ventricle (mostly right) with fibrosis
- Restrictive: storage of f.i. iron/glycogen/amyloid in the heart
Fatty changes of only the right ventricle of the heart is found in: a) dilated cardiomyopathy b) hypertrophic cardiomyopathy c) restrictive cardiomyopathy d) arrhythmogenic cardiomyopathy
d) arrhythmogenic cardiomyopathy
Is it common to find a tumor in the heart?
No, it’s rare
What type of tumor is mostly seen in the heart?
Metastases
Where are the metastases of the heart seen?
Can be everywhere! Ventricles, atria, blood vessels, even the valves
What is more common benign or malignant tumors in the heart?
benign
What is the most common benign tumor of the heart? what is seen microscopically?
Myxoma (cause unknown), there is vessel proliferation
Where is the benign tumor often found?
Atria
What is the malignant type of tumor in the heart, and where can it be found?
Angiosarcoma (malignant tumour of blood vessels), can be everywhere (very poor prognosis)
What is NOT a complication of acute myocardial infarction? a. Death b. Rupture of the myocardial wall c. Lymphocytic myocarditis d. Arrhythmia
c. Lymphocytic myocarditis Myocardial infarction causes cardiac inflammation (including a diffuse increase of lymphocytes) Lymphocytic myocarditis shows mainly lymphocytes that form aggregates: this is caused by a viral infection and can be the CAUSE of an acute myocardial infarction
