Cardiovascular pathology Flashcards
What is cardiomyopathy?
Any disease f the cardiac muscle often resulting in changes in the size of the heart chambers and thickness of the heart wall
What is dilated cardiomyopathy?
A large weak and flabby heart. 2-3 times the normal size but the normal weight.
Non speific histological features
What are teh causes of dilated cardiomyopathy?
50% genetic effecting genes which code for heart muscle proteins eg. Desmin or dystrophin. X linked or mitochondrail
Toxins- alcohol (direct toxic effect of ethanol on myocardium. Doxorubicin- chemotherapy that is cardiotoxic used in lymphomas
Rarely: Cardiac infection or pregnancy
What are the clinical features of dilated cardiomyopathy?
General picture of heart failure: SOB, oedema, poor exercise tollerance and cardiac output
What is hypertrophic cardiomyopathy?
Big solid, muscle bound heart with heavy and strong contraction. Esp large septum
Diastolic dysfunction as the heart cannot relax and fill eventually leading to outflow obstruction and sudden death in atheletes
What are the causes of Hypertrophic cardiomyopathy?
Majority are genetic- any of teh genes which code for muscle tissue
Beta myosin heavy chain, Myosin binding protein C, alpha tropomyosin
What is seen at autopsy in hypertrophic cardiomyopathy (often clinically silent)?
Large interventricualr septum
Assymetrical heart with outflow tract obstruction and left ventricular luminal reduction
Large heart supplied by the same coronary arteries => ischemia
What can been seen in the histology in hypertrophic cardiomyopathy?
Disorganised myofibril/swirls which do not contract regularly
What is restrictive cardiomyopathy?
A stiff heart which causes a lack of compliance (complience is the relaxation of the heart during diastole)
Little elastic tissue => incomplete filling and diastolic dysfunction
Heart looks normal- you may see bilateral atrail dilation due to back pressure.
Do not necessarily have thick walls
What are the causes of restrictive cardiomyopathy?
Deposition of something in the myocardium
Metabolic byproducts like iron
Amyloid
Sarcoidosis- multisystem granulomatous disorder
Tumours of the heart or fibrosis (possibly following radiation)
What is amyloid disease?
Abnormal deposition of abnormal proteins
Many different types of proteins which form beta pleated sheets and the body cannot get rid of them
Amyloid is divided into 5 classes. What is the AA classification?
Related to chronic diseases like rheumatoid
Amyloid is divided into 5 classes. What is the AL classification?
Related to abnormal light chains in abnormal immunoglobulin
Amyloid is divided into 5 classes. What is the haemodialysis associated classification?
Beta 2 mycroglobulin
Amyloid is divided into 5 classes. What is the familial classification?
Transthyretin and other inherited forms
Amyloid is divided into 5 classes. What is the diabetes or alzhimers disease classification?
Amyloid associated with diabetes or alzhimers
Amyloid affects the heart. Can it affect anywhere else?
Some can. Some are isolated to the heart like senile cardiac amyloidosis
What is seen in histology of amyloid?
Heavy heart
Waxy pink material which stains positively for congo red and exhibits apple green birefringence. These are the diagnostic tests
What happens when amyloid proteins enter the SA/AV node?
Arrhythmias and death
What is arrhythmogenic right ventricular dysplasia?
Genetic autosomal dominant with low penitrance
What are the signs of arrhythmogenic right ventricular dysplasia?
Syncope and funny turns
Arrhythmias and occasionally sudden death in young, fit males
How is arrhythmogenic right ventricular dysplasia diagnosed?
Hard to diagnose
Right ventricle is largely replaced by adipose tissue which is big, floppy and non contractile => arrythmias
What is myocarditis?
inflammation of the heart
What are the causes of myocarditis?
Infectious (most common) and non infectious causes:
Viral (coxackie A+B, echovirus) bacterial, fungal, protozoal, helminth
Changa’s disease in S America
Lyme’s disease Borrelia burgdorferi
HIV virus