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71 Cards in this Set
- Front
- Back
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what percentage of people over 60 have atrial fibrillation?
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2-5%
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what is the most common symptom of AF?
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rapid irregular palpitations
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how does AF appear on an ECG?
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absent P waves, finely undulating baseline (fibrillation waves), irregular QRS complexes with an average rate of 150-200 bpm
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what are the two major complications of AF?
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heart failure and embolism
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what is the percentage risk of serious thromboembolism in patients with AF?
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5% per year
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what induces vasodilatation during pregnancy?
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progesterone
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which organ does not have increased blood flow during pregnancy?
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brain
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how much does plasma volume increase in pregnancy?
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40%
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which valve is most often affected in rheumatic fever?
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mitral
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which arrythmia is most commonly associated with rheumatic heart disease?
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AF
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what percentage of people with rheumatic heart disease have no history of rheumatic fever?
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50%
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which valves are most often affected in RHD?
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mitral and aortic
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which arrhythmia is commonly associated with RHD?
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AF
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what percentage of patients with acute rheumatic fever will develop chorea?
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10-15%
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what cross reacts with cardiac myosin in rheumatic fever?
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streptococcal M-protein
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what cross-reacts with myocardial sarcolemma?
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streptococcal membrane proteins
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what cross-reacts with heart valve glycoprotein?
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capsule hyaluronate
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what components of the immune system are deposited in the heart during acute carditis?
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immunoglobulin and complement
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what is the characteristic histological feature of rheumatic carditis?
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mononuclear cell infiltrate (predominantly of T cells)
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which HLA genes are associated with ARF?
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HLA-DR2 and HLA-DR4
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what is rheumatic fever?
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nonsuppurative acute inflammatory complication of infection due to certain strains of beta-haemalytic Group A streptococcus pyogenes
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what are the skin manifestations of rheumatic fever?
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subcutaneous nodules
erythema marginatum |
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at what age does RF usually occur?
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5-15 years
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what is the incidence of RF?
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0.1-3% of those with streptococcal infections
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what is the latent period between streptococcal pharyngitis and the initial episode of acute RF?
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1-5 weeks (average 19 days)
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what characterises RF?
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arthritis
chorea carditis skin manifestations |
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what is the average duration of RF?
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3 months or longer
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describe the valve involvement in rheumatic heart disease
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acute interstitial valvulitis
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what happens to untreated valves in rheumatic heart disease?
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valve thickening, fusion, retraction of leaflets and cusps
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t/f... antibiotics modify an acute RF attack
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false
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why is a regimen of antibiotics prescribed for acute RF?
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to eradicate any remaining GAS
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what is the treatment goal in treating acute RF?
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suppress inflammation and avoid a rebound
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what causes endocarditis?
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directly - microbial colonisation of the endocardium
indirectly - RF |
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what microorganisms are causative in most cases of infective endocarditis?
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streptococci
staphylococci |
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what are the initial symptoms of infective endocarditis?
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low grade fever
anorexia fatigue anaemia splenomegaly |
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t/f... anticoagulation with heparin is indicated for infective endocarditis
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false
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how does the body increase central venous pressure?
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muscle pump
sympathetic innervation of veins reduced blood flow to kidney |
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what is preload?
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central venous pressure (filling pressure for heart)
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what is afterload?
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arterial BP (pressure into which the heart has to pump)
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t/f... hypertension increases the work of the heart
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true
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what is involved in pancarditis?
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fibrinous pericarditis
myocarditis endocarditis |
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which antibodies to streptococcal enzymes are demonstrable in rising titre in RF?
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anti-streptolysin O
anti-DNase B anti-streptokinase anti-hyaluronidase |
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what exacerbates tissue damage in acute RF?
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auto-immunity may develop to antigens provided by damaged cardiac tissue
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how does ARF affect the joints?
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migratory polyarthritis with temporary pain and swelling
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what percentage of children with RF develop carditis?
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50-75%
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what are the risk factors for ARF?
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lower standards of living, especially crowding
socially and economically disadvantaged populations |
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what are the clinical features of ARF?
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migratory polyarthritis
carditis subcutaneous nodules erythema marginatum Sydenham chorea |
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what are the acute effects of RF on the heart?
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myocarditis
arrythmias and cardiac failure (occasionally) |
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what is often described as a bread and butter pericarditis?
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acute fibrinous pericarditis
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what is the mechanism of acute fibrinous pericarditis?
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exudation of fibrin into pericardial cavity stimulating fibrous adhesions between parietal and visceral pericardium
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what is involved in rheumatic myocarditis?
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immunological inflammation (granulomatous) leads to development of Aschoff nodules close to blood vessels
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what is an Aschoff nodule?
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possible central necrosis
foci of swollen eosinophilic collagen surrounded by lymphocytes (mainly T cells), occasional plasma cells and plump macrophages (Anitschkow cells, Aschoff multi-nucleated giant cells) |
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which cells are pathognomonic for RF?
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Anitschkow cells (plump macrophages)
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describe the vegetations that occur in acute rheumatic endocarditis
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small, nodular, pale thrombi firmly attached to valve cusps
consist of fibrin and platelets but no micro-organisms |
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where do rheumatic vegetations occur?
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lines of apposition of valves
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what is the result of organisation of vegetations on valve cusps?
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cusps become thicker and more rigid due to fibrosis
cusp vascularity increases cusp calcification (adds to the rigidity) |
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what type of overload occurs with hypertension and aortic stenosis?
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pressure overload
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what type of overload occurs with mitral regurgitation?
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volume overload
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what happens to the lung in chronic left heart failure?
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brown induration: brown foci of haemosiderin, lung parenchyma firm due to - blood vessel congestion, alveolar oedema, fibrosis
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which ventricle will fail more rapidly and why?
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right ventricle
thinner wall and thus a smaller functional reserve |
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what is the appearance the liver in chronic venous congestion?
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nutmeg liver
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what happens to the spleen in chronic venous congestion?
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grossly enlarged
prominent pale fibrinous trabeculae |
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what are the manifestations of systemic venous congestion?
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elevation of JVP
pitting oedema ascites and effusions |
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what changes are exhibited in the failing heart?
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severe dilatation of all chambers
hypertrophy of walls of all chambers but most evident in ventricles |
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t/f... stable atherosclerotic plaques are at a low risk of rupture
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true
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when should surgery be undertaken in aortic stenosis?
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once the lesion reaches moderate severity
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what type of overload is caused by aortic regurgitation?
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volume overload
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t/f... aortic regurgitation is better tolerated than aortic stenosis
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true
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what type of pulse occurs with aortic regurgitation?
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bounding pulse
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t/f... mitral stenosis is well tolerated
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true
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which valvular pathology has the poorest prognosis?
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aortic stenosis
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