Cardiovascular pathology Flashcards
What is meant by cardiomyopathy?
Any disease of the cardiac muscle
What are the 5 main types of cardiomyopathy?
Dilated cardiomyopathy
Restrictive cardiomyopathy
Hypertrophic cardiomyopathy
Arrhythmogenic right ventricular dysplasia
Cardiac amyloidosis
What occurs pathologically in dilated cardiomyopathy?
The heart becomes around 2-3 times larger than the normal heart and has floppy walls
What are some causes of dilated cardiomyopathy?
Genetics (50%)
Toxins
Alcoholism
Doxorubicin (Chemotherapy agent)
Myocarditis
Childbirth
What are some clinical features of dilated cardiomyopathy?
Shortness of breath
Low ejection fraction
What occurs pathologically in hypertrophic cardiomyopathy?
The heart becomes large and solid
The heart walls become hypertrophic with strong contraction, however, it causes narrowing of the chambers, leading to decreased filling in diastole
What is the main cause of hypertrophic cardiomyopathy?
Genetics - Most commonly ß-myosin heavy chain, myosin binding protein C or alpha tropomyosin genes mutated
What occurs in restrictive cardiomyopathy?
A lack of compliance of the heart walls leads to a stiff wall that won’t contract, causing diastolic dysfunction
What are the main causes of restrictive cardiomyopathy?
Deposition (Iron, amyloid, sarcoid)
Tumours
Radiation fibrosis
What is the main cause of arrhythmogenic right ventricular dysplasia?
Genetic - Autosomal dominant with low penetrance
What occurs pathologically in arrhythmogenic right ventricular dysplasia?
The right ventricle becomes largely replaced by fat and becomes large and floppy
What is amyloid?
An abnormal deposition of any protein
What structure do proteins take in amyloid?
ß-Pleated sheets
What are the 2 main classes of amyloid?
AA amyloid - Associated with chronic diseases
AL (light chain) - Associated with abnormal immunoglobulin in haematological cancers
What are some common diseases that involve amyloid?
Amyloid deposition in the Islets of Langerhan’s in type I diabetes
Amyloid deposition in the brain in Alzheimers
What are some examples of amyloidosis affecting the cardiovascular system?
Abnormal atrial natriuretic peptide
Senile cardiac amyloidosis (Transthyretin build up)
Haemodialysis associated amyloidosis (ß2 microglobulin build up)
What does amyloid look like under a microscope?
It looks like a pink, waxy material
It stains positive for congo red stain
It exhibits apple green birefringence
What are the main viral causes of myocarditis?
Coxsackie A and B
ECHO virus
What are some atypical viruses that can cause myocarditis?
Chagas disease - trypanosomiasis
Borellia burgdorferi - Lyme’s disease
HIV
What virus causes Lyme’s disease?
Borellia burgdorferi
What are some non-infectious causes of myocarditis?
Hypersensitivity such as in rheumatic fever
SLE
What are aschoff bodies?
Rheumatic granulomas formed by macrophages such as Aschoff cells and Anitchkov cells that surround collagen fibres and collagen necrosis
What is formed by rheumatic myocarditis?
Aschoff bodies
What is the most common cause of pericarditis?
ECHO virus
What is usually seen pathologically in pericarditis?
A discoloured, clear liquid in the pericardium
What would be seen in pericarditis caused by Mycobacterium tuberculosis?
A suppurative (Cheesy) inflammation
What is Dressler’s syndrome?
Pericarditis post Myocardial Infarction due to immune reaction to damaged heart muscle
