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47 Cards in this Set
- Front
- Back
Prerequisites for developing infective endocarditis
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1) ABNORMAL OR DAMAGED ENDOTHELIUM
2) High flow and pressure 3) Transient bacteria 4) organisms with special characteristics - gram pos and oral bacteria |
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What usually causes a damaged endothelium?
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Inflammation (ie., from rheumatic fever), trauma, or a virulent microorganism
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Why are Gram-Positive Cocci more likely to cause infective endocarditis?
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Staphylococci and Streptococci have proteins on their surface that bind fibrin, fibrinogen, fibronectin and platelets
Most gut gram-negative rods are susceptible to complement lysis in the blood (serum-sensitive) |
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What does the vegetation consist of?
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fibrin-platelet clots that form where endothelium is damaged/abnormal
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Only _____ and ____ cause endocarditis with great frequency due to their specific tropism and adherence
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staph and strep
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______ strep describe alpha hemolytic oral strep of multiple species
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Viridans
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Group of small, fastidious pleomorphic gram-negative coccobacilli that live in the moutha nd are associated with periodontal disease
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HACEK
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How do the Viridans strep and HACEKs enter the bloodstream?
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Usually from the mouth after dental manipulations or in people with poor oral hygeine
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How does Staph aureus enter the bloodstream?
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Through minor skin break, inapparent infection, or a grossly infect wound. Drug addicts can also inject normal S aureus on the skin into the vein.
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How does enterococci enter the bloodstream?
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From the gut
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Symptoms of subacute bacterial endocarditis
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Vague and nonspecific - fever, malaise, fatigue. May have rheumatology, neurologic, renal, cardiac or pulmonary manifestations.
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Classical way to dx SBE
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1) positive blood cultures
2) predisposing, usually valvular, cardiac lesion 3) peripheral embolic phenomena |
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What test is used to dx SBE?
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transesophageal echo
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Endocarditis should be suspected in anyone with _________ bacteremia
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S aureus
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Most impt single factor in dxing endocarditis
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+ blood cultures
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T/F Blood cultures should be continuously positive in IE regardless of the time they are obtained
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T
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__ positive cultures are usually enough to dx IE, although ___ are usually obtained to cover contamination and fastidious organisms.
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2-3; 6
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How are blood cultures drawn?
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In pairs - two separate sterile venipunctures drawn simultaneously from opposite arms.
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How is the antibiotic determined?
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It must be bactericidal because vegetations are protected from normal body defenses.
In vitro susceptibility testing must be performed. |
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How long is antibiotic therapy given?
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Prolonged duration - at least two weeks, up to 6
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T/F Antibiotic Therapy must be parenteral to assure continuous serum levels.
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T
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when is antibiotic prophylaxis tx given?
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Whenever someone at high risk for IE undergoes a procedure associated with significant transient bacteremia (ie, dental work, oral surgery, etc.). These include persons with damaged, abnormal or prosthetic heart valves and those with certain congenital cardiac defects.
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How do IV drug users differ from classical endocarditis?
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They're younger, higher M:F ratio, lower prevalence of underlying structural heart disease.
It's predominantly <b>right-sided</b> with tricuspid involved in 80%. 80% is S. Aureus |
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Most common infecting organism in IV drug users
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S. Aureus
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Most common infecting organism in prosthetic valve endocarditis
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S. epidermidis. They're hospital-acquired, almost always require surgical replacement.
Viridans strep are second. |
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Most gut gram-____ rods are susceptible to complement lysis in the blood (serum-sensitive)
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negative
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IV drug users are more likely to acquire IE on the ____ side while classically it occurs on the ____ side
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Right; Left
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What are causes of culture-negative endocarditis?
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Prior treatment
Difficult-to-culture organisms: Bartonella henselae; Tropheryma whippelii; Coxiella burnetii; fungi |
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What are some important bactericidal abx for txing IE?
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Beta-lactams (penicillins and cephalosporins)
Vancomycin Aminoglycosides (gentamicin) Fluoroquinolones (for RARE gram-negative endocarditis) |
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The “test of cure” for a patient with endocarditis is the ______ after therapy has been discontinued.
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ABSENCE OF RELAPSE, not the disappearance of signs and sx.
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T/F Cardiovascular disease is the leading cause of death in both genders
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T
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There is altered (systolic, diastolic) compliance with aging
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diastolic
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3 changes in CV system with age
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diminished cardiovascular response to stress
altered diastolic compliance alterations in response to therapies |
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the max heart rate (increases, decreases) with age
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decreases
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the max O2 uptake (increases, decreases) with age
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decreases
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How does the diastolic LV wall thickness change with aging?
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Thickness increases
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What is the impact of Preload Changes (EDV) on the Ventricular Performance in aging?
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Resting left ventricular volumes increased in older subjects
Wide variations in preload produced a normal Frank-Starling response in both older and younger subjects |
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Presbycardia: defn
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impaired cardiac function attributed to aging
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How is preload changed in aging?
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decreased
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How is contractility changed in aging?
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no change!
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How is heart rate changed in aging?
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attenuated at all levels of exercise.
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How is afterload changed in aging?
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no attenuation
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What drugs are given to improve preload attenuation in aging?
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Diuretics
Nitrates |
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T/F Digoxin usage decreases mortality
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F
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(Systolic, Diastolic) hypertension remains a significant independent cardiovascular risk factor
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Systolic
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Predominant sx of ischemic heart disease in elderly
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dyspnea
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For high risk pts, LDL < ___; for very high risk pts, LDL < ___
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100; 70
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