Cardiovascualr System 2 Flashcards
What is stenosis
Failure of a valve to open completely
This impedes the forward flow of blood
What is incompetent regurgitation
Failure of the valve to close completely
Allows the reverse flow of blood
What can valvular heart disease affect
Pure or mixed regurg or stenosis
Single or multiple valves
What is functional regurgitation
Valve becomes incompetent due to dilation of a ventricle
What does the clinical consequences of valvular heart disease depend on
Which valve
Degree of impairment
Rate of it’s development
Rate and quality of compensatory mechanisms
Can go from being physiologically unimportant to severe and rapidly fatal
What causes valvular incompetence
Intrinsic disease of the valve cusps or damage to or distortion of the supporting structures Aorta Mitral valve annulus Tendinous cords Papillary muscle Ventricular free wall \+/- underlying valve abnormality ACUTE OR CHRONIC
Valvular stenosis
Acute or chronic
Is the valve abnormal in this
Usually chronic
Almost always has an underlying valve abnormality
Where can valvular calcification occur
Calcific aortic stenosis
Calcification of a congenitally bicuspid aortic valve
Mitral annular calcification
What are heart valves subjected to
High repetitive mechanical stress especially at hinge points of cusp/leaflet
40 million cycles a year
Substantial tissue deformation
Transvalvular pressure gradients - aortic 120mmHg mitral 80mmHg
Cumulative damage is complicated by dystrophic calcification
Causes and epidemiology of calcific aortic stenosis
Age related wear and tear calcification
Clinically apparent 70-80 yo
Calcification of bicuspid valve occurs earlier
Most common cause of mitral stenosis
Rheumatic heart disease
Most common cause of mitral incompetence
Floppy mitral valve
Myxomatous degeneration
Mitral valve prolapse
Most common cause of aortic stenosis
Calcification of normal and congenitally bicuspid aortic valves
Most common cause of aortic incompetence
Dilation of ascending aorta related to hypertension and age
Mitral regurgitation facts
Most common form of valvular heart disease in the industrialised world
One or both mitral leaflets enlarged, hooded, redundant so prolapsed back into atrium during systole
Usually incidental finding on examination - mitral valve prolapse
Very rarely - sudden death
What is rheumatic fever
Acute immunologically mediated multisystem inflammatory disease
Occurs a few weeks after group A beta haemolytic streptococcal pharyngitis
Thought to be a hypersensitivity reaction induced by group A streptococci
Features:
Migratory polyarthritis of large joints
Carditis
Subcutaneous nodules
Skin rash
Syndenham chorea - neurological disorder (purposeless movements)
What is rheumatic heart disease
Acute leads to pancarditis Endocardium --> vegetations Myocardium --> Aschoff bodies Pericardium --> pericarditis Reactivation with subsequent pharyngeal infections --> cumulative damage
What is the most important complication of rheumatic fever
Chronic rheumatic heart disease
Characterised by
Deforming fibrotic valvular disease esp mitral stenosis
Fish mouth/button hole stenosis
Leaflet thickening, commissural fusion and shortening, thickening and fusion of chordea tendinea
Can cause permanent dysfunction
Most frequent cause of mitral stenosis
End stage of organisation of acute inflammatory damage
What is infective endocarditis
Serious infection
Colonisation/ invasion of the heart valves
Formation of friable bulky vegetations - composed of thrombotic debris and organisms
Often underlying tissue destruction
Most cases are BACTERIAL
Infective endocarditis types
Acute and subacute.
Characteristics of acute infective endocarditis
High virulence Valve previously normal Acute onset 50% mortality days to weeks Lesion is necrotising, ulcerative and invasive
Characteristics of subacute infective endocarditis
Low virulence
Insidious onset
Most recover weeks to months
Less destructive
What causes a predisposition to infective endocarditis
Abnormal valve - Floppy mitral valve Degenerative calcific valvular stenosis Bicuspid aortic valve Artificial valve (Vascular graft) Host factors - Immunosuppression - neutropenia, immunodeficiency, therapeutic
Diabetes
Alcohol
IV drug use
What are the organisms involved in infective endocarditis
Alpha-haemolytic strep - abnormal valve 50-60%, subacute
Staph aureus (skin) high virulence, normal valve, IV drug users
Mouth commensals - most of rest
Staph epidermidis - prosthetic valves
How does the person get infected
Dental or surgical procedure
Dirty needle
Trivial injury
What should be done for those at risk
Prophylactic antibiotics
Morphology of infective endocarditis
Aortic and mitral valve most commonly affected
Tricuspid valve in IV drug users
Bulky friable vegetation
May involve more this one valve
Complications of infective endocarditis
Myocardial abscess Valve rupture/perforation Systemic emboli- L sided body -kidney R sided - lungs Septic emboli Immune complexes
What is non bacterial thrombotic endocarditis
Deposition of fibrin/platelet thrombi on valve leaflets -SMALL Occur on either side of the heart Occurs on a previously normal valve Sterile Non-destructive Clinical importance = emboli Occurs in hypercoagulable state - Disseminated intravascular coagulation Cancer sepsis
What are the types of artificial valves
Mechanical
Bioprostheses
- homografts
- chemically treated animal (porcine) valves
Complications of artificial valves
Thromboembolic - need long term coagulation
Infective endocarditis
Structural deterioration - esp bioprostheses
What is a cardiomyopathy
Heart disease resulting from a primary abnormality in the myocardium
What are the causes of a cardiomyopathy
Inflammatory Immunological Systemic metabolic disorders Muscular dystrophies Genetic abnormalities of the cardiac myocytes - cardiac energy metabolism - structural and contractile proteins Idiopathic
What are the 3 clinical pictures of cardiomyopathy
Dilated cardiomyopathy DCM 90%
Hypertrophic cardiomyopathy HCM
Restrictive cardiomyopathy least common
Within each group - spectrum of diversity and overlap of features between groups
Each pattern can be idiopathic , specific identifiable cause
Or secondary to extramyocardial disease
Diagnoses - endomyocardial biopsies of RV
What is dilated cardiomyopathy characterised by
Progressive - Cardiac hypertrophy Dilation Contractile Dysfunction Leads to congestive cardiac failure
Causes of dilated cardiomyopathy
Most idiopathic Alcohol Peripartum Genetic (ox phos, beta ox FFA, dystrophin) Myocarditis Haemochromatosis Chronic anaemia Drugs - doxorubicin, adriamycin Sarcoidosis
What is the morphology of dilated cardiomyopathy
Gross Heavy heart 2-3x normal Large flabby Dilation in all chambers Mural thrombi common - thromboemboli \+/- secondary mitral/tricuspid regurg Normal coronary arteries Histology - Non specific Hypertrophied fibres Attentuated/ stretched fibres Interstitial and endocardial fibrosis
Clinical features of dilated cardiomyopathy
any age 20-60 Slowly progressive CCF But can be sudden compensated --> decompensated functional state EF 25% 50% mortality in 2 years Death - progressive CCF - arrhythmia Embolism Treatment cardiac transplant
What is hypertrophic cardiomyopathy characterised by
Myocardial hypertrophy
Abnormal diastolic filling
1/3 intermittent left ventricular outflow obstruction
Heavy muscular hyper contracting heart
What is the gross morphology of hypertrophic cardiomyopathy
Massive myocardial hypertrophy
No ventricular disease
Asymmetric septal hypertrophy (10% symmetric)
What is the histology of hypertrophic cardiomyopathy
Extensive myocyte hypertrophy
Myocyte disarray
Interstitial fibrosis
What is the pathogenesis of hypertrophic cardiomyopathy
50% genetic 50% sporadic Genetic autosomal dominant with variable penetrance Many difference mutations in 4 genes that encode contractile proteins (sarcomeres) 1) B- myosin heavy chain 2) cardiac troponin T 3) alpha - tropomyosin 4) myosin binding protein C
Clinical features of hypertrophic cardiomyopathy
Basic abnormality - Dec chamber size + poor compliance + Dec stroke volume
Clinical problems Angina AF Cardiac failure Ventricular arrythmias Sudden death
What is restrictive cardiomyopathy
Primary Dec in ventricular compliance -> impaired ventricular filling
What are the causes of restrictive cardiomyopathy
Idiopathic
Radiation fibrosis
Amyloidosis
Sarcoidosis
Metastatic tumour
Products of inborn errors of metabolism
Endomyocardial fibrosis (children in tropical areas)
Endocardial fibroelastosis (young children)
Many of these can be diagnosed by endomyocardial biopsy
Features of restrictive cardiomyopathy
Normal sized ventricles
Normal sized ventricular chambers
Both atria dilated
Firm myocardium
What is myocarditis
Inflammatory process of the myocardium which results in injury to the cardiac myocytes
Causes of myocarditis
Infection - esp viruses most common
Immune - post viral, post strep (rheumatic fever), SLE, drug hypersensitivity, transplant rejection
Unknown sarcoidosis
Clinical features of myocarditis
Asymptomatic could lead to dilated cardiac myopathy years later
Or could lead to arrythmias, acute heart failure, sudden death
Types of Pericardial disease
Pericardial effusion- fluid variety of compositions e.g. Transudate and exudate
Haemopericardium- blood
Purulent pericarditis - pus
What is pericardial disease called when it is large and rapidly developing
Cardiac tamponade
How can a haemopericardium form
Ruptured MI
Traumatic perforation
Ruptured aortic dissection
What is pericarditis
Pericardial inflammation
Secondary to cardiac disease , thoracic or systemic disorders, or metastasis from distant site
Causes of pericarditis
Infection Virus Bacteria TB Fungi Immune mediated : Rheumatic fever SLE Scleroderma Post MI dressier syndrome Drug hypersensitivity Miscellaneous: MI Uraemia Post cardiac surgery. Neoplasia Trauma Radiation
What are the types of pericarditis
Serous Fibrinous Purulent/suppurative Haemorrhaging Caseous
What are the outcomes of pericarditis
Reabsorbed
Resolve
Organise -> obliterate pericardial space
+/- constructive pericarditis = heart is surrounded by dense fibrous scar that limits diastolic expansion of the heart and restricts cardiac output
What is a neoplasm of the heart called and how common are they
Myxoma
Rare
5% of people dying from cancer
Most commonly a primary tumour
Where is the most likely location of a myxoma
90% are located in the atria -most left
Called an atrial myxoma
What is the gross morphology and what problems can it cause
Sessile or pedunculated
Cause
Half valve obstruction
Injury to the valve
Embolisation
What is congenital heart disease
Abnormalities of the heart or great vessels present at birth
What are the 3 main categories of congenital heart disease
1) left to right shunt
2) right to left shunt
3) obstructions
What is a shunt
Abnormal connection between chambers or blood vessels
Blood flows from high to low pressure
What is a right to left shunt and what are the consequences of this
Blood shunted from the pulmonary to the systemic circulation
Therefore the blood is less oxygenated -> cyanosis
Cyanosis congenital heart disease
Conditions associated with right to left shunts
Tetralogy of fallot - most common
Transposition of the the great arteries
Persistent truncus arteriosus
Tricuspid atresia
Total anomalous pulmonary venous connection
Can get paradoxical embolus
Veins bypass lungs to systemic circulation
What is a left to right shunt
Blood shunted from systemic to pulmonary army circulation
Consequences of a left to right shunt
Increased pulmonary blood flow
-> pulmonary hypertension.
Reversible initially but need early treatment
With time -> reversal of shunt (high to low pressure)
-> late cyanosis (eisenmengers syndrome)
ASD
VSD- most common
PDA
AV septal defect
What cause obstruction
Chamber
Valve blood
vessel
Abnormal narrowing
What is vasculitis
Inflammation of wall of blood vessel
Cause of vasculitis
Immune : Immune complex Antineutrophil cytoplasmic antibodies Direct antibody mediated Cell mediated Inflammatory bowel disease Paraneoplastic Infectious: Unknown Giant cell (temporal) arteritis- most common Takayasu arteritis Polyarteritis nodosum
Consequences of vasculitis
affect specific blood vessels
Different patterns
Small vessel - skin - rash
Kidney glomerulonephritis
Aetiology of vasculitis
Infection - acute or chronic, bacterial viral fungal Neoplasm benign, malignant Cardiovascular system Haematological Infiltrates e.g. Amyloid, sarcoid Autoimmune Drugs / chemicals Unknown idiopathic
