Infective Endocarditis & Valve Disease Flashcards
State at least 4 causes of infective endocarditis
Poor dental hygiene, IVDU, soft tissue infection, dental treatments, IV cannulae/lines, cardiac surgery inc pacemakers - all lead to bacteraemia
State 2 pathogens that cause acute infective endocarditis
Staphylococcus aureus, Streptococcus pyogenes
State at least 5 pathogens that cause subacute infective endocarditis
Streptococcus viridans, Staphylococcus epidermis, Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella, Coxiella, Mycoplasma, Candida
Where does acute endocarditis usually spread?
Aorta
Where does subacute endocarditis usually spread?
Chordae (thick, strong, tendinous connections between the mitral valve cusps and the papillary muscles, also known as heart strings)
Describe the clinical features of infective endocarditis
Constitutional: fever, malaise, rigors, anaemia
Cardiac: new murmur, usually MR
Immune: Roth spots, Osler’s nodes, glomerulonephritis -> haematuria
Thromboembolic: Janeway lesions, septic abscesses (in lungs, brain, spleen, or kidney), microemboli, splinter haemorrhages, splenomegaly
Which group of patients typically get right-sided infective endocarditis?
IV drug users
Which criteria are used to diagnose infective endocarditis?
Duke criteria - 2 major, or 1 major + 3 minor, or 5 minor
State the two major criteria for diagnosing infective endocarditis
Positive blood culture growing typical infective endocarditis organisms OR two positive cultures of atypicals >12h apart
Evidence of vegetation or abscess on echocardiogram or new regurgitant murmur
State the five minor criteria for diagnosing infective endocarditis
Risk factor (e.g. prosthetic valve, IVDU, congenital valve abnormalities), fever >38, thromboembolic phenomena, immune phenomena, positive blood cultures not meeting major criteria
How is subacute endocarditis usually treated?
Depending on cause. Example regime benzylpenicillin + gentamicin for 4 weeks, or vancomycin for 4 weeks
How is acute endocarditis treated?
Flucocloxacillin
If MRSA, rifampicin + vancomycin + gentamicin
Describe the pathophysiology of aortic stenosis
Narrowed aortic valve causes high velocity, high pressure flow
Describe the pathophysiology of aortic regurgitation
Incompetent aortic valve allows blood flow back into the left ventricle after systole
Describe the pathophysiology of mitral stenosis
Narrowed mitral valve causes high velocity, high pressure flow. Back pressure leads to left atrial dilatation
Describe the pathophysiology of mitral regurgitation
Incompetent mitral valve allows blood flow back into the left atrium during systole
State two causes of aortic stenosis
Calcification with age, congenital bicuspid valve
State at least three causes of aortic regurgitation
Infective endocarditis, dissecting aortic aneurysm, left ventricular dilatation, connective tissue disease (e.g. Marfan, ankylosing spondylitis)
State the main cause of mitral stenosis
Rheumatic fever
State at least three causes of mitral regurgitation
Infective endocarditis, connective tissue disease, post-MI, rheumatic fever, left ventricular dilatation (functional MR)
What is chronic rheumatic valve disease?
Thickening of the valve leaflet, especially along lines of close, and fusion of commissures post-rheumatic fever, with thickening, shortening, and fusion of chorea tendineae. Mainly affects mitral valve, sometimes aortic, rarely tricuspid, almost never pulmonary.
Describe the typical presentation of mitral valve prolapse
Middle-aged woman with shortness of breath and chest pains. On examination, mid systolic click and late systolic murmur
State the five types of pericarditis, and a cause of each
Fibrinous (MI, uraemia), purulent (Staph), granulomatous (TB), haemorrhagic (tumour, TB, uraemia), fibrous/ constrictive (any cause of pericarditis)
What is the most common cause of pericardial effusion?
Chronic heart failure
