Term
| what needs to happen in order for endocarditis to occur? |
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Definition
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Term
| why is alpha strep (viridans) one of the most common organisms that causes endocarditis? |
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Definition
| b/c it lives in your mouth and gains entry to your bloodstream (bacteremia) everytime you brush your teeth (another common entry is bowel movement) |
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Term
| what other other common mechanisms of aquiring bacteremia? |
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Definition
| direct invasion, travel through lymphatics |
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Term
| how does endocarditis compare to sepsis? |
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Definition
| endocarditis is more continuous, and is not considered a septic syndrome (sepsis implies hemodynamic and vascular collapse) |
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Term
| what helps clear bacteria from the blood? |
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Definition
| the reticuloendothelial system, lymphatic system, multiple macrophages and lymphocytes that occur in the blood and visceral organs |
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Term
| why do gram - bacteria infrequently cause endocarditis? |
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Definition
| they lack the fibronectin proteins on cell surfaces which attract gram + bacteria and allows them to stick. **therefore you see gram + associated with endocarditis far more commonly |
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Term
| what bacteria cause more nonendocarditic bacteremia? endocarditic? |
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Definition
| beta hemolytic (groups A,B,G) vs streptococcus mutans, bovis, & dextran + mitior |
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Term
| why is endocarditis often called subacute bacterial endocarditis? |
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Definition
| b/c it is very slow, can take up to 2-3 months before a characteristic lesion is visible (with the exception of some bacteria, such as staph. aureus which can cause massive tissue destruction quickly) |
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Term
| what is the characteristic presentation of endocarditis? what bacteria is usually the cause? |
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Definition
| turbulent blood flow in the endocardium, causing an inflammatory response, which leads to platelet aggregation, thrombi, fibrin deposits - which bacteria stick to and cause more of an inflammatory response. layering of inflammatory cells and bacteria continue, which leads to charateristic vegetation. in these more normal cases, alpha/viridans strep is generally the cause. |
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Term
| how do pts with endocarditis present clinically? what is an important consideration? |
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Definition
| fever, fatigue, ill for a month, no appetite - no specific complaint. PEs are important to consider with this disease |
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Term
| other than the heart valves, what parts of the heart can be affected by endocarditis? |
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Definition
| septal defects, chordae tendineae, or simply on the mural endocardium |
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Term
| how does inflammation affect the endothelium of the heart valves? |
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Definition
| inflammation doesn't allow the endothelium to have tight junctions and allows for inflammatory mediators to stick |
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Term
| what is the initial stages of endocarditis? |
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Definition
| generally you have an initially non-bacterial thrombotic endocarditis which is an inflammatory response with the formation of early sterile vegetation (which is the endpoint for some diseases such as marantic and libman-sacks) |
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Term
| where does endocarditis typically occur? |
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Definition
| in the aortic or mitral valve (b/c they have the highest level of turbulent blood flow), usually not both at the same time |
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Term
| how common is endocarditis on the tricuspid valve? |
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Definition
| not common unless the pt is an IV drug abuser |
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|
Term
| who does IE typically affect? |
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Definition
| the elderly (esp those with rheumatic fever - mitral stenosis), except for young IV drug abusers |
|
|
Term
| why are cases of IE going up? how many cases are there estimated per year? |
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Definition
| b/c more of the elderly are living longer. 10-15,000 IE cases are estimated per year |
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Term
| what is the most common bacteria to infect native valves? |
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Definition
| staph aureus, viridans strep, and enterococci in that order |
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Term
| what are the common bacteria to infect prosthetic valves early (<60 days), late (>60 days), and a year? |
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Definition
| early: staph epi, late: staph aureus or epi, after a year: same as native valves (staph aureus, viridans strep, and enterococci in that order) |
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Term
| why is staph aureus common in IV drug users? |
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Definition
| staph aureus such as pseudomonas and serraia live in water - and IV drug users will often lick their needles |
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Term
| what are you at much higher risk for with staph aureus endocarditis? |
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Definition
| tissue damage, and thus embolic events (very bad in CNS) and death |
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|
Term
| can staph aureus endocarditis result as a consequence of medical progress? |
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Definition
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|
Term
| **what are high risk factors for endocarditis? |
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Definition
| prosthetic cardiac valve, prior episodes of endocarditis, complex congential cardiac defects, surgically constructed systemic-pulmonary shunts or conduits. |
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Term
| **what are moderate risk factors for endocarditis? |
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Definition
| patent ductus arteriosus, ventricular septal defect, primum atrial septal defect, coarcation of the aorta, bicuspid aortic valve, hypertrophic cardiomyopathy, acquired valvular dysfunction, MVP w/mitral regurgitation |
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Term
| **what are low risk factors for endocarditis? |
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Definition
| isolated secundum atrial septal defect, ASD/VSD/PDA >6 mo past repair, "innocent" heart murmur by auscultation in the pediatric population and "innocent" heart murmur by echocardiography in the adult population |
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Term
| what native valvular lesions have the highest incidence of endocarditis in > and <65 yr old pts? |
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Definition
| >65: degenerative, <65:MVP |
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|
Term
| what is the highest risk factor in pts under 40 years old? |
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Definition
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|
Term
| how can valve replacement create a new disease? |
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Definition
| IE develops in 1-4% of valve recipients during the 1st year and about 1% thereafter |
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|
Term
| why is staph aureus now the leading cause of endocarditis? |
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Definition
| nosocomial endocarditis involving staph is usually a complication of bacteremia induced by an invasive procedure/vascular device (esp if in the RA) |
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Term
| do pts with IE commonly have a pre-existing structural cardiac abnormality |
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Definition
| yes about 3/4. congenital heart disease is seen in about 10-20% cases of IE |
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|
Term
| what are the most common predisposing congenital heart lesions? |
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Definition
| bicuspid aortic valves, PDA, VSD, coarctation of the aorta |
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|
Term
| when does bicuspid aortic valve typically lead to stenosis? |
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Definition
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Term
| does simply the fact that a pt has had IE put them at a higher risk for it in the future? |
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Definition
| yes, it is possible that these pts have some defect in immunologic surveillance that allow them to get endocarditis more than once, even without a known valvular lesion |
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Term
| are HIV pts more at risk for endocarditis? |
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Definition
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|
Term
| what is the risk increase for endocarditis for pts w/MVP? what is a common finding w/these pts? |
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Definition
| 5-8x due to ensuing mitral regurgitation which causes increased blood flow as well as turbulence. leaflet redundancy with myxomatous degeneration is a frequent finding |
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|
Term
| how does age inform risk for IE w/MVP between age and genders? |
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Definition
| males with MVP have a lower risk under 40, and women with MVP have a lower risk over 40 |
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|
Term
| can pregnancy be considered a risk for endocarditis? why? |
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Definition
| yes, b/c it creates a hyperdynamic state w/a high volume of blood |
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|
Term
| do central venous catheters, pulmonary artery catheters, catheters for chronic dialysis present a risk for IE? |
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Definition
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|
Term
| if someone has strep bovis endocarditis, what else needs to be investigated? |
|
Definition
| carcinomas, 5-8% association between primary colon disease |
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|
Term
| what are the top 5 organisms responsible for bacteremia? what is the issue with the #1 organism? |
|
Definition
| coagulation negative staph, staph. aureus, enteroccus, fungus, yeast candida, and gram negative rods in that order. the problem with coagulase negative staph is that it is not only the most common cause of bacteremia, but also the most common contaminant - therefore it is hard to determine if it is a contaminant or a true pathogen. coagulase negative staph is also problematic b/c it doesn't cause many symptoms at first |
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Term
| what are the clinical manifestations of IE? |
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Definition
| mostly nonspecific, looks like a typical viral illness: fever, chills, weakness, dyspnea, sweats, anorexia, weight loss. **except for skin manifestations such as petechiae, splinter hemorrhages, and osler’s nodes |
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Term
| what kind of metastatic complications might you see with pts w/valvular lesions onf the R side of the heart? |
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Definition
| lung abscess, empyema, multiple septic emboli, cavitary lesions |
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Term
| what kind of metastatic complications might you see with pts w/valvular lesions onf the L side of the heart? |
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Definition
| mycotic aneurysm, splenic infarction, splenic abscess, brain abscess, septic arthritis, renal stuff-see frequently |
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|
Term
| what are kidney lesions due to IE called? |
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Definition
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|
Term
| how are subconjunctival petechial hemorrhages observed? |
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Definition
| just pull down the eyelid |
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|
Term
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Definition
| antigen-antibody depositions that are very painful (differentiates them from janeway lesions) circular lesions that are whitish in color and have erythema around them |
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Term
| what is a splinter hemorrhage? |
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Definition
| bleeding under the fingernail, distally: usually due to trauma, proximally: usually due to endocarditis |
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|
Term
| what is usually seen on pts with subacute endocarditis? |
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Definition
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|
Term
| what are janeway lesions? |
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Definition
| non-painful/not on distal tops of fingers and toes (differentiates them from oslers) petechiae |
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|
Term
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Definition
| central optic spot associated with IE |
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|
Term
| what kind of aneurysm is seen with IE? how is this screened for? |
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Definition
| mycotic aneurysms are a big complication with endocarditis - most of which are not symptomatic. this is screened for with mental status changes/neurologic exam |
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Term
| what is another issue other than mycotic aneurysms that can affect the brain associated with IE? |
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Definition
| brain abcesses, which result from septic emboli to the brain. they don't always follow the typical vascular distrobution, so they can be in multiple/atypical locations |
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|
Term
| can the eyes be affected by endocarditis? |
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Definition
| yes, there can be a layer of infection in the iris -> referred to as hypopyon |
|
|
Term
| can vertebral discs be affected by IE? |
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Definition
| yes, which often co-present with osteomyelitis and epidural abscesses |
|
|
Term
| what is the major criteria for the "duke dx" of IE? |
|
Definition
| an echocardiogram w/a visible abnormality, w/a regurgitant jet or dehisced prosthetic valve |
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|
Term
| what is an important part of testing blood for endocarditis? |
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Definition
| pts have to have persistent blood cxs |
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|
Term
| what is the most common cause of cx-negative endocarditis? |
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Definition
| getting previous antibx (can affect postive cx for up to 2 wks), though staph aureus will give positive cx no matter what |
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Term
| beyond bloodwork, what other tests can be determine EI? |
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Definition
| an elevated ESR and/or CRP (except with CHF). most subacute pts quickly develop a normochromic normocytic anemia, and the WBC count may be normal or elevated |
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|
Term
| why would someone with IE have red urine? |
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Definition
| most pts with IE have glomerulonephritis, so there are RBCs in urine |
|
|
Term
| what are the different kinds of echocardiography that can determine IEs? |
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Definition
| echos should be performed on all pts suspected of IE, and of the 2 kinds, a TTE (transthoracic) is only 60% sensitive while a TEE (transesophageal) is sensitive 90% of the time |
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|
Term
| what are the major duke criteria for IE? |
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Definition
| positive strep bovis or *nutritionally variant strep (require iron or sugars, tested for by ability to grow next to staph aureus in a column), a *HACEK organism (haemophilus species, actinobacillus, cardiobacterium, eikenella, and kingella) - gram negative that live in the mouth, and have a strong association with IE, *enterococci w/out a primary focus. postive blood cx 12 hrs apart, oscillating mass on an echo w/a regurgitant jet, obvious absecss or new dehiscence of a valve |
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|
Term
| what are the minor duke criteria for IE? |
|
Definition
| predisposition, fever, vascular phenomenon, immunologic phenomenon, echo w/vegetation - but not regurgitant jet |
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|
Term
| what needs to be true about bacteremia consisting of enterococci in order for IE to be considered? |
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Definition
| the enterococci cannot have a primary focus |
|
|
Term
| is coxiella burnetti able to cause endocarditis? |
|
Definition
| yes, it can be transmitted from animals or person to person via aerosolizatoin |
|
|
Term
| does group B strep always cause IE? are there risk factors? what if people do get it? |
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Definition
| no, but if the pt has these risk factors: diabetes, alcohol, neoplasia, chronic infection, chronic foley catheters, cirrhosis, chronic neurologic patients, spinal bifida, or GSW in quad - the risk increases. if people do get infected with this, the mortality rate goes up to 50% (similar to staph aureus) |
|
|
Term
| how common is pneumococcal endocarditis? what is it associated with? |
|
Definition
| uncommon, when pts do get it, alcoholic liver disease or alcoholic liver disease resulting in splenic disease is usually at root due to a lack of Igs or splenic sequestration due to portal HTN. it is encapsulated, so there is less of a chance for opsonization if they are lacking Ig. |
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|
Term
| what is the likelihood of gram negative IE? |
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Definition
|
|
Term
| what are the HACEK organisms? what kind of IE do they usually cause? |
|
Definition
| haemophilus species, actinobacillus, cardiobacterium, eikenella, and kingella - which are usually responsible for subacute like viridans strep. they can cause frequent emboli b/c often dx late w/big vegetations |
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|
Term
| what is the most common reason for cx negative IE? what bacteria are associated with these? |
|
Definition
| previous antibx therapy. infection w/bartonella, coxiella, chlamydia (uncommon), mycoplasma, t. whippeli (whipple’s disease) need to be considered for cx negative IE |
|
|
Term
| what kind of antibx should be used for IE? |
|
Definition
| bactericidal, for 6-8 wks |
|
|
Term
| what is the tx for viridan strep? |
|
Definition
|
|
Term
| what is the tx for enterococci? |
|
Definition
|
|
Term
| what is a risk for pts with skin only MRSA? |
|
Definition
| progression to IE, toxic shock syndrome |
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|
Term
| **what are indications for sx w/pts w/IE? |
|
Definition
| CHF refractory to medical therapy, persistent infection after a week of appropriate therapy, and recurrent serious emboli (particularly in the presence of large vegetations) |
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|
Term
| **what are indications for IE prophylaxis? |
|
Definition
| previous IE, prosthetic valve, congenital cyanotic heart disease w/prosthetic shunts in the first 6 mo after repair, repaired CHD w/residual effects (still open space on echo), cardiac transplants w/valvular disease |
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