Cardiomyopathies Flashcards
What is a cardiomyopathy?
Any disease of cardiac muscle; leads to changes in size of heart chambers and heart thickness
What are the classifications of cardiomyopathy?
Dilated
Restrictive
Hypertrophic
What are some of the causes of dilated cardiomyopathy?
genetics
alcohol - common in alcoholics
chemotherapy agents - doxorubicin
Clinical features of dilated cardiomyopathy?
General picture of heart failure; dyspnoea pulmonary oedema fatigue RVF emboli AF VT
What are some of the signs of dilated cardiomyopathy?
raised pulse and JVP
decreased BP
low ejection fraction (low CO)
displaced apex
What is the effect of a hypertrophic heart on contraction?
strong contraction
Hypertrophic myopathy causes dysfunction of systole or diastole?
diastole (not systolic since contraction fine)
diastolic dysfunction - heart cannot relax
what are some of the genes involved in hypertrophic cardiomyopathy?
sarcomere-related genes:
beta-myosin heavy chain
myosin binding protein C
What would you see on biopsy of hypertrophic cardiomyopathy?
disorganised swirls of myofibrils
What is the type of inheritance of hypertrophic obstructive cardiomyopathy?
autosomal dominant
What might an ECG of hypertrophic cardiomyopathy show?
LVH progressive T wave inversion deep Q waves (inferior & lateral leads) AF WPW syndrome ventricular ectopics VT
What would an ECHO show of hypertrophic cardiomyopathy?
asymmetrical septal hypertrophy
small LV cavity with hyper-contractile posterior wall
What medication would you give for symptomatic benefit of hypertrophic cardiomyopathy?
b-blocker or verapamil - aim is to reduce ventricular contractility
Which anti-arrhythmic drug might a person with a hypertrophic cardiomyopathy need, and why?
diastolic dysfunction - so heart can’t relax…therefore need something to either slow HR or increase time between APs…
Type 3 are rhythm control of atria or ventricles
So, give amiodarone to increase AP duration and effective refractory period
What would you have to consider when giving amiodarone as an anti-arryhthmic?
age of patient - amiodarone has adverse effects when used in the long run
if used along with a beta-blocker or verapamil then there is increased risk of bradycardia
Why would you give a person with hypertrophic cardiomyopathy an anti-coagulant?
for paroxysmal AF or systemic emboli
What are main features of restrictive cardiomyopathy?
lack of compliance stiff heart diastolic dysfunction (doesn't fill well) can look normal bi-atrial dilatation
What causes atrial dilatation in restrictive cardiomyopathy?
back pressure from stiff ventricles
What are the main causes of restrictive cardiomyopathy?
deposition of something in the myocardium: amyloidosis sarcoidosis haemochromatosis tumours fibrosis
How would a restrictive cardiomyopathy present?
feature of RVF raised JVP hepatomegaly oedema ascites
What is the sign for amyloidosis on biopsy?
stains positive for ‘congo red’
waxy pink material
exhibits apple green bienfringence
What would an ECG of restrictive cardiomyopathy look like?
low voltage conduction abnormalities, e.g. AV block or SA node dysfunction
Which cardiomyopathy involves largely the replacement of the right ventricle with fatty material?
Arrythmogenic Right Ventricular dysplasia
What does penetrance of genetic disease mean?
penetrance describes the proportion of individuals with a disease-causing mutation who exhibit clinical symptoms
Why is arrhythmogenic right ventricular dysplasia difficult to diagnose?
the RV normally looks quite fatty
range of non-specific symptoms (syncope & palpitations during exercise)
sudden death can be first time it presents
What is myocarditis?
inflammation of the myocardium
What are the common viral causes of myocarditis?
Coxsackie A and B HIV Enterovirus Hepatitis Mumps
Which autoimmune conditions are associated with myocarditis?
SLE
scleroderma
sarcoid
heart transplant rejection
What would the myocardium look like in infectious myocarditis?
thickened and ‘beefy’
Which type of hypersensitivity reaction is non-infectious myocarditis?
type IV
Hypersensitivity to drugs causes which type of myocarditis?
eosinophilic myocarditis
Hypersensitivity to infection causes ?
rheumatic fever after strep sore throat
Which gram positive group of organisms causes the classical sore throat?
streptococcus - Group A Strep
What changes occur to the heart in rheumatic fever?
patchy inflammation of myocardium
short, thick chordae tendinae
mitral stenosis with thickening & fusion of valve leaflets
What does SLE stand for?
Systemic Lupus Erythematous
Which valves does SLE involve?
mitral or tricuspid
What are aschoff bodies?
nodules found in the heart in rheumatic fever;
contain fibrinoid collagen necrosis and abnormal macrophages
What is pericarditis?
inflammation of pericardial layers
Characteristic symptoms of pericarditis?
central chest pain
relieved sitting forwards
What would you typically see on ECG of pericarditis?
saddle-shaped ST elevation (V5&6)
What are the causes of pericarditis?
DR IS TRUMP Dressler's syndrome Radiotherapy Infection SLE TB Rheumatic fever (immune mediated) Uraemic (renal failure) Malignancy Post-MI (24-48hrs)
Which type of infections cause a purulent pericardial effusion?
bacterial (TB) and fungi
ECHO virus would produce what type of pericardial effusion?
serous
What causes Dressler’s syndrome?
Assumed to be immune mediated; myocardial injury stimulus formation of autoantibodies against heart muscle
What are symptoms of Dressler’s syndrome?
Recurrent fever & chest pain
± pleural or pericardial rub
cardiac tamponade may occur
What is endocarditis?
inflammation of heart lining but generally refers to inflammation of heart valves
What are the risk factors of infectious endocarditis?
rheumatic heart disease prosthetic / bicuspid valves congenital defects calcific disease IV drug abuse septicaemia
What is the basic pathogenesis of endocarditis?
Damages heart valve causes turbulent blood flow over roughened endothelium.
Platelets and fibrin deposited (thrombi), upon which bacteria settle and form a vegetation.
Which side of the heart is usually affected in infective endocarditis?
left side
Which heart valve is most likely infected in PWIDs?
tricuspid
Which organism will most likely infect a prosthetic valve?
staph epidermis
Which organism is most likely to cause infective endocarditis in PWIDs?
staph aureus
candida
Which organisms make up HACEK?
Haemophilus Aggregatibacter Cardiobacterium Eikenella Kingella
What gram stain are HACEK?
gram negative
Which antibiotics would you give for native valve endocarditis?
amoxicillin IV
gentamicin IV
Which antibiotic would you give for drug user endocarditis?
flucloxacillin IV
Which antibiotics would you give if you suspected MRSA?
vancomycin IV
rifampicin PO
gentamicin IV
Which antibiotics would you give for prosthetic valve infection?
vancomycin IV
rifampicin PO
gentamicin IV
What is the commonest coagulase -ve Staph organism?
staph epidermis
How long are antibiotics given for?
4-6 weeks
Which organism is most likely to cause native valve endocarditis?
staph aureus
What are Janeway lesions?
non-tender, small haemorrhage nodal lesions on palms or soles of feet
What are Roth spots?
retinal haemorrhages with white/pale centres
What are Osler’s nodes?
painful, raised red lesions on hands and feet
What are signs on ECHO of endocardial involvement?
vegetation, abscess or new valvular regurgitation
What does staph epidermis usually contaminate?
skin
prosthetic material
Which organism is 2nd most common cause of native valve endocarditis?
strep viridians
What is NBTE?
Non-bacterial Thrombotic Endocarditis
non-infectious endocarditis
What are the risk factors for NBTE?
embolic disease
hyper-coagulable states
What predisposes you to hyper-coagulable states?
MI oral contraceptive pill post-surgery malignancy pregnancy SLE
What is the cause for Libman-Sacks endocarditis?
lupus
Which valve does SLE endocarditis affect?
mitral particularly
What is a carcinoid tumour?
neoplasms of neuroendocrine cells
What is carcinoid syndrome?
when a carcinoid tumour has spread to the liver
What does a neuroendocrine tumour produce in excess?
hormones
Which hormones do a carcinoid tumour produce?
histamine
serotonin
bradykinin
What is the effect of bradykinin on the vasculature?
inflammatory mediator - blood vessels dilate
Which anti-hypertensive drugs increase bradykinin effect?
ACE inhibitors block bradykinin degradation
What is the effect of serotonin on the vasculature?
vasoconstriction
What is the effect of histamine on the vasculature?
vasoconstriction -> bronchoconstriction
Why are primary tumours of the heart rare?
cardiac muscle cells are end-differentiated
What is the commonest tumour of the heart? Which chamber is it found?
atrial myxoma
left atrium
What are some of the complications of an atrial myxoma?
valve obstruction: tumour emboli and endocarditis
Which diseases might an atrial myxoma mimic?
infective endocarditis
mitral stenosis
What are some of the overlapping signs & symptoms of atrial myxoma and infective endocarditis?
clubbing
fever
weight loss
systemic emboli
What are some of the overlapping signs & symptoms of atrial myxoma and mitral stenosis?
left atrial obstruction
AF
