Other cardiovascular pathology Flashcards
What are the three main forms of valvular heart disease?
pure or mixed
affect single or multiple valves
1) stenosis = valve is too narrow and fails to open completely, impeding blood flow forwards
2) incompetence (regurgitation) = failure of the valve to close completely, reverse flow of blood
3) functional regurgitation = valve becomes incompetent due to dilatation of a ventricle
What factors are important to consider in terms of the clinical consequences of a valvular disorder?
dependent upon:
- which valve is impaired
- degree of impairment
- rate of disease development (rate and quality of compensatory mechanisms)
How does the severity of valvular heart disease vary?
range from physiologically unimportant (rheumatic mitral stenosis) to severe and rapidly fatal (acute aortic incompetence)
How can valvular incompetence arise?
due to intrinsic disease of the valve cusps, or damage to/distortion of supporting structures (aorta, papillary muscles and tendinous cords)
Can be superimposed on underlying valve abnormality
Acute or chronic condition
What is the usual underlying cause of valvular stenosis including examples?
Valvular stenosis almost always has an underlying valve abnormality (chronic)
- valvular calcification = form of stenosis that affects aortic and mitral valves
e. g. mitral annular calcification, calcific aortic stenosis (common with age) and calcification of a congenitally bicuspid aortic valve (normally 3 cusps)
What is the mechanism causing valvular stenosis?
heart valves subject to high repetitive mechanical stress, especially at the hinge points of the cusps therefore cumulative damage is further complicated by dystrophic calcification
What is mitral incompetence?
myxomatous degeneration and mitral valve prolapse
- very common
often both mitral valves will become enlarged, hooded and redundant causing them to prolapse back into the left atrium during systole
- very rarely it can lead to sudden death
What is a common cause of mitral stenosis?
rheumatic fever - due to acute immunologically mediated inflammatory disease that follows infection with group A beta-hemolytic strep
Other than mitral stenosis what are the other associated symptoms caused by rheumatic fever?
migratory polyarthritis of large joints, carditis, subcutaneous nodules, skin rash, and sydenham chorea
What can happen to the heart in acute rheumatic heart disease?
pancarditis
- endocardium will form vegetations
- myocardium will form inflammatory foci with aschoff bodies
- pericardium will be inflamed
this damage can accumulate with repeated infections leading to chronic rheumatic heart disease
What is chronic rheumatic heart disease characterized by?
deforming fibrotic valvular disease (fish mouth) with leaflet thickening
commissural fusion and shortening
thickening and fusion of the tendinous cords
What is infective endocarditis?
serious (usually bacterial) infection that colonise the heart valves = results in the formation of friable bulky vegetations with underlying tissue destruction
- acute and subacute forms
What are the characteristics of acute infective endocarditis ? (virulence, valve, presentation, outcome, lesion, organisms)
virulence= high valve= previously normal presentation= acute onset outcome = 50% mortality in days-weeks lesion= necrotising, ulcerative, invasive organisms= staph aureus
What are the characteristics of subacute infective endocarditis ? (virulence, valve, presentation, outcome, lesion, organisms)
virulence= low valve= usually abnormal presentation= insidious onset outcome = recover in weeks-months lesion= less destructive organisms= alpha hemolytic strep, mouth commensals, staph epidermis
What factors predispose you to infective endocarditis?
abnormal valves immunosuppression diabetes alcoholism IV drug use e.g. anything that can lead to bacteraemia - dental procedures
Which valves are most commonly affected by endocarditis?
aortic and mitral valves are most commonly affected - however tricuspid is often affected with IV drug use
What endocarditis in the tricuspid valve due to IV drug use lead to ?
formation of vegetations myocardial abscess valve rupture systemic emboli septic emboli immune complex formation
What does non-bacterial thrombotic endocarditis involve?
deposition of fibrin and platelet thrombi on valve leaflets - can be on either side of the heart and will affect previously normal valves
As it is sterile it is a non-destructive process but can cause emboli
When does non-bacterial thrombotic endocarditis typically occur?
hypercoaguable states such as DIC, cancer and sepsis
What are the 2 main forms of artificial valves?
mechanical and bioprothesis (often porcine xenografts)
What are the complications of artificial valves?
thromboembolic hence long term anticoagulants must be taken
increase susceptibility to infective endocarditis and
structure deteriorates through age
What is cardiomyopathy?
heart disease resulting from a primary abnormality in the myocardium
caused by: inflammation, immunological disease, systemic metabolic disorders, muscular dystrophies and genetic myocyte abnormalities or it can be idiopathic
What are the 3 main clinical pictures of cardiomyopathy?
1) dilated cardiomyopathy
2) hypertrophic cardiomyopathy
3) restrictive cardiomyopathy
- each has a spectrum of severity and there can be overlap between them
How are cardiomyopathies diagnosed?
endomyocardial biopsy of the right ventricle
What are the characteristics of dilated cardiomyopathy?
progressive hypertrophy
dilation
contractile dysfunction
leads to congestive cardiac failure
What are the causes of dilated cardiomyopathy?
most cases are idiopathic alcohol peripartum genetic myocarditis hemochromatosis chronic anaemia chemotherapy sarcoidosis
What are the morphological changes seen in dilated cardiomyopathy?
2-3x heavier than normal with dilation of all chambers - may be mural thrombi as well as mitral and tricuspid regurgitation
coronary arteries will be normal
Histologically, what can be seen in dilated cardiomyopathy?
fibres will be hypertrophied and attenuated
there will also be fibrosis
What are the clinical features of dilated cardiomyopathy ?
slowly progressive congestive heart failure occur at any age
Ejection fraction can be as low as 25% leading to a high rate mortality from arrhythmia or heart failure
- treatment is cardiac transplant
What are the characteristics of hypertrophic cardiomyopathy?
myocardial hypertrophy with abnormal diastolic filling - consists of heavy muscular hyper contracting heart
- no ventricular dilation
- asymmetrical septal hypertrophy
- extensive myocyte hypertrophy and disarray with interstitial fibrosis
What type of inheritance is hypertrophic cardiomyopathy?
usually autosomal dominant with variable penetrance there are many different mutations in four genes that encode sarcomeres
- 1) beta myosin heavy chain
- 2) cardiac troponin T
- 3) alpha tropomyosin
- 4) myosin binding protein C
What are the clinical features of hypertrophic cardiomyopathy?
decreased chamber size coupled with poor compliance = decreased SV
What clinical problems are associated with hypertrophic cardiomyopathy?
angina atrial fibrillation cardiac failure ventricular arrhythmia sudden death
What is restrictive cardiomyopathy due to?
What can cause restrictive cardiomyopathy?
caused by radiation fibrosis, amyloidosis, sarcoidosis, metastatic tumor, inborn error in metabolism, endomyocardial fibrosis and endocardial fibroelasotosis
What are the clinical features of restrictive cardiomyopathy?
heart ventricles and chambers will be normal sized
both atrial will be dilated and the myocardium will be fine
What is myocarditis?
inflammatory process of the myocardium = injury to myocytes
What can cause myocarditis?
viral infection
sarcoidosis
immune causes: post-viral, post-streptococcal, SLE, drug hypersensitivity and transplant rejection
Clinically how can myocarditis present?
either be asymptomatic and later result in DCM
or
lead to arrthymia and acute heart failure with sudden death
What is pericardial effusion?
fluid of a variety of compositions occupies the pericardial sac
- if the fluid is large enough and rapidly develops it can lead to cardiac tamponade
What are the different compositions of fluid that can occur in pericardial effusion?
- transudate = clear fluid forms against a pressure gradient
- exudate = forms in inflammation and contains proteins
- haemopericardium = fills the pericardium with blood and can be due to ventricular rupture
- purulent pericarditis = thick pussy exudate
What is pericarditis?
inflammation of the pericardium - can be secondary to cardiac disease, thoracic or systemic disorders or metastasis from a distant site
What are the causes of pericarditis?
infections
immune mediated
miscellaneous
What are the different types of pericarditis?
serous fibrinous purulent hemorrhagic caseous
What can happen to the fluid in pericarditis?
it can be reabsorbed, resolve itself or become organized and obliterate the pericardial space - this can lead to constrictive pericarditis if the heart becomes surrounded by dense fibrous tissue scar tissue
What is the most common type of neoplasm of the heart?
primary are very rare but secondary are much more common
- most common primary tumor= benign atrial myxoma - attached to the endocardium and projects out into the heart lumen
What can benign atrial myxoma cause?
ball-valve obstruction, injury to the valve and embolisation
What are the 3 main categories of congenital heart disease?
1) R-L shunts
2) L-R shunts
3) Obstructive
What are R-L shunts?
reduce oxygenation of the blood causing cyanosis
can be due to tetralogy of fallot, transposition of great vessels, persistent trunks arterioles, tricuspid atresia and total anomalous pulmonary venous connection
What are L-R shunt?
lead to pulmonary hypertension by increasing pulmonary blood flow
with time shunt reverses
can lead to eisenmenger’s syndrome and late cyanosis = due to atrial and ventricular septal defects or patent ductus arteriosus
What is obstructive congenital heart defects?
block flow due to an abnormal narrowing of a chamber, valve or blood vessel
eg. coarctation of the aorta
What is vasculitis?
inflammation of the wall of a blood vessel
- can be caused by infection, immune complex formation, ANCA antibodies, T-cell mediated destruction, inflammatory bowel disease or neoplasms
- different patterns of disease occur, affecting specific sizes of vessels as well as causing rashes and affecting the kidneys
