STEP2: IE Flashcards
(58 cards)
1
Q
What is infective endocarditis (IE)?
A
An infection of the endocardium that typically affects one or more heart valves.
2
Q
What is the most common cause of bacteremia leading to IE?
A
Dental procedures, surgery, distant primary infections, and nonsterile injections.
3
Q
What are the two types of infective endocarditis based on the onset of symptoms?
A
- Acute IE
- Subacute IE
4
Q
Which pathogen is most commonly associated with acute bacterial endocarditis?
A
Staphylococcus aureus.
5
Q
Which pathogen is most commonly associated with subacute bacterial endocarditis?
A
Viridans streptococci.
6
Q
What are some clinical features of infective endocarditis?
A
- Fatigue
- Fever
- Chills
- Malaise
- New or changed heart murmur
- Signs of heart failure
7
Q
What is the purpose of the 2023 Duke-ISCVID criteria?
A
To assess the likelihood of infective endocarditis.
8
Q
What is the initial treatment for infective endocarditis?
A
Empiric IV antibiotics.
9
Q
In which patients is IE prophylaxis recommended?
A
Patients with congenital heart disease undergoing certain dental procedures.
10
Q
True or False: IE is typically fatal if left untreated.
A
True.
11
Q
List some typical pathogens that may indicate infective endocarditis.
A
- Staphylococcus aureus
- Enterococcus faecalis
- Viridans streptococci
- HACEK group
12
Q
What are the main risk factors for infective endocarditis?
A
- Male sex
- Age > 60 years
- Acquired valvular disease
- Prosthetic heart valves
- Previous IE
13
Q
Fill in the blank: The most commonly affected valve in individuals who inject drugs is the _______.
A
[tricuspid valve]
14
Q
What are some common cardiac manifestations of infective endocarditis?
A
- Development of a new heart murmur
- Tricuspid valve regurgitation
- Aortic valve regurgitation
- Mitral valve regurgitation
15
Q
What are Osler nodes?
A
Painful nodules on pads of the fingers and toes caused by immune complex deposition.
16
Q
What is the classification of infective endocarditis based on the acuity of the infection?
A
- Acute bacterial endocarditis
- Subacute bacterial endocarditis
17
Q
What is the primary pathogen in early-onset prosthetic valve endocarditis?
A
Coagulase-negative staphylococci.
18
Q
What is the most common pathogen associated with right-sided endocarditis?
A
S. aureus.
19
Q
What is the significance of drawing three sets of blood cultures?
A
To confirm the diagnosis of infective endocarditis before initiating antibiotic treatment.
20
Q
What are some extracardiac manifestations of infective endocarditis?
A
- Petechiae
- Janeway lesions
- Microabscesses
- Neurological manifestations
21
Q
What are the major criteria for the 2023 Duke-ISCVID criteria?
A
- Typical pathogens in blood cultures
- Characteristic findings on echocardiogram
- Surgical evidence of IE
22
Q
True or False: Viridans streptococci is the most common cause of subacute IE in healthy valves.
A
False.
23
Q
Fill in the blank: The most commonly affected valve in native valve endocarditis is the _______.
A
[mitral valve]
24
Q
What is the IgG titer level indicative of Bartonella quintana on IFA for infective endocarditis (IE)?
A
≥ 1:800
This titer level is a major criterion for diagnosing IE.
25
What are the major criteria for diagnosing infective endocarditis (IE) according to the 2023 Duke-ISCVID criteria?
* Characteristic findings of IE on echocardiogram and/or cardiac CT scan (e.g., new valvular regurgitation)
* 18F-FDG PET/CT scan with findings suggestive of IE
* Surgical evidence of IE on direct tissue inspection during cardiac surgery
* Positive blood cultures that fulfill major criteria
26
What constitutes minor criteria for the diagnosis of infective endocarditis (IE)?
* Predisposing heart abnormality
* Injection drug use
* History of IE
* CIED
* Fever > 38°C (100.4°F)
* Vascular phenomena
* Immunologic phenomena
* Positive blood cultures not fulfilling major criteria
27
What is the interpretation of 'Definite IE' based on the Duke-ISCVID criteria?
* ≥ 1 pathological criterion
* ≥ 2 major criteria
* 1 major criterion and ≥ 3 minor criteria
* ≥ 5 minor criteria
28
What are the laboratory findings that may indicate disease severity in infective endocarditis (IE)?
* CBC: leukocytosis, leukopenia, anemia, thrombocytopenia
* Inflammatory markers: ↑ CRP, ↑ ESR
* Urinalysis: Hematuria and/or nephritic sediment
29
What is the initial test of choice for patients with suspected infective endocarditis (IE)?
Transthoracic echocardiography (TTE)
## Footnote
Transesophageal echocardiography (TEE) is considered in selected cases.
30
What are the indications for considering transesophageal echocardiography (TEE) in diagnosing infective endocarditis (IE)?
* Presence of high-risk features
* TTE findings inconclusive or suggestive of IE
* Concern for intracardiac complications
31
What are the echocardiographic findings that constitute major criteria for diagnosing infective endocarditis (IE)?
* Valvular vegetations
* Abscess
* New valvular regurgitation
* New partial prosthetic valve dehiscence
32
What are the clinical features of noninfective endocarditis (nonbacterial thrombotic endocarditis)?
* Valves and cardiac function rarely impaired
* Vegetations easily dislodged
* Asymptomatic until embolization occurs
33
What is the treatment for noninfective endocarditis?
* Anticoagulation with heparin
* Treatment of the underlying condition
34
What is the management strategy for unstable patients with suspected infective endocarditis (IE)?
Use the ABCDE approach and initiate management of sepsis as needed.
35
What are the empirical antibiotic therapy regimens for infective endocarditis (IE)?
* Vancomycin
* PLUS a beta-lactam (e.g., ceftriaxone OR cefepime)
* PLUS gentamicin and rifampin in selected cases
36
What are the indications for surgical consult in infective endocarditis (IE)?
* Prosthetic valve IE
* Valve dysfunction causing heart failure
* Uncontrolled infection
* Perivalvular extension or complications
* High embolic risk
37
What is the purpose of endocarditis prophylaxis?
To prevent bacteremia in patients with high-risk cardiac features prior to certain procedures.
38
What are some procedures that require infective endocarditis prophylaxis?
* Dental procedures (e.g., tooth extraction)
* Invasive respiratory procedures
* Placement of a CIED
* Surgical placement of prosthetic cardiac material
39
Fill in the blank: The 2023 Duke-ISCVID criteria have replaced the _______ for diagnosing infective endocarditis.
modified Duke criteria
40
Early onset versis later onset IE; what pathogens
Early Onset: Coagulase negative organisms like staph epi
Late Onset: viridians strep, staph a
Early-onset is often due to perioperative contamination (think S. epidermidis), while late-onset resembles NVE (think Viridans strep, S. aureus).
41
Pathogens implicated in native valve endocarditis
Native Valve Endocarditis: Viridans group streptococci and S. aureus are the most common culprits overall.
42
Pathogens implicated in IV drug use endocarditis
IV Drug Use: Strongly associated with Staphylococcus aureus and often involves the tricuspid valve.
43
pathogens seen in IE from dental procedures
Dental procedures/Poor oral hygiene: Think Viridans group streptococci.
44
pathogens seen in IE from GI/GU procedures
enterococci
45
Examples of procedures that do NOT require prophylaxis for IE
Examples of procedures that do NOT require prophylaxis: Routine anesthetic injections through non-infected tissue, taking dental radiographs, placement/adjustment of removable prosthodontic or orthodontic appliances, shedding of deciduous teeth, bleeding from trauma to the lips or oral mucosa.
Respiratory Tract Procedures: Prophylaxis is NOT routinely recommended unless the procedure involves incision or biopsy of the respiratory mucosa and the patient has one of the high-risk cardiac conditions.
Gastrointestinal (GI) or Genitourinary (GU) Procedures: Prophylaxis is NOT recommended solely to prevent IE for routine GI or GU procedures (e.g., colonoscopy, EGD, cystoscopy) in the absence of active infection.
| Antibiotic prophylaxis should be considered in patients with asplenia wh
46
Streptococcus gallolyticus can cause IE, typically in association with ____________
colorectal cancer.
47
When do we give patients with asplenia bacterial prophylaxis for IE?
asplenic patients may receive antibiotic prophylaxis for infective endocarditis (IE) if they undergo procedures with a high risk of bacteremia, e.g., tooth extraction. These procedures, however, do not include orthodontic bracket placement. This patient will undergo a dental procedure with a low risk of infection with encapsulated bacteria or bacteremia and she has no other indications for endocarditis prophylaxis (e.g., history of IE); therefore, no antibiotic prophylaxis is indicated.
48
the most common cause of subacute IE in damaged native heart valves
Viridans streptococci, such as S. sanguinis, are the most common cause of subacute IE in damaged native heart valves (e.g., bicuspid aortic valve). Because viridans streptococci are part of the normal oral flora and can be introduced into the blood following dental procedures, patients with certain types of congenital heart disease (e.g., unrepaired cyanotic heart defects) should receive antibiotic prophylaxis prior to invasive dental procedures.
49
A group of fastidious organisms that are normally part of the oral and pharyngeal flora. These organisms can cause infective endocarditis.
HACEK organisms
50
HACEK organisms such as Cardiobacterium hominis are highly susceptible to a certain group of antibiotics.
Third-generation cephalosporins, such as ceftriaxone, have a broad spectrum coverage against gram-negative bacteria and are the treatment of choice for infective endocarditis caused by HACEK organisms.
## Footnote
Third generation cephalosporins
A class of cephalosporin antibiotics that includes ceftriaxone, cefotaxime, and others. Active against many gram-negative bacteria but are less active against gram-positive bacteria than first-generation cephalosporins. Ineffective against Enterococcus, Listeria, and MRSA; has variable activity against Pseudomonas.
51
Which valves are most commonly affected in Left-Sided Infective Endocarditis, and what are the primary risk factors?
Valves: Mitral valve (most common overall), Aortic valve.
Primary Risk Factors: Pre-existing valvular heart disease (rheumatic, degenerative), prosthetic heart valves (especially late-onset).
52
Where do emboli from left-sided IE typically travel, and what are the classic (and most feared) complications?
Embolization: To the systemic circulation.
Classic Complications: Stroke (most common and feared), systemic infarcts (kidney, spleen), heart failure, perivalvular abscess.
Peripheral Stigmata (less common now): Janeway lesions, Osler's nodes, Roth spots, splinter hemorrhages.
53
Which valves are most commonly affected in Right-Sided Infective Endocarditis, and what is the classic primary risk factor?
Valves: Tricuspid valve (most common right-sided), Pulmonic valve (rare).
Classic Primary Risk Factor: Intravenous Drug Use (IVDU).
Other Risk Factors: Indwelling venous catheters (central lines, hemodialysis).
54
Where do emboli from right-sided IE typically travel, and what are the classic complications?
Embolization: To the pulmonary circulation.
Classic Complications: Septic pulmonary emboli (leading to cough, dyspnea, pleuritic chest pain, hemoptysis, pulmonary infarcts, lung abscesses).
Peripheral Stigmata: Less common than in left-sided IE.
55
A patient presents with fever and a new murmur. What symptoms would strongly suggest left-sided IE vs. right-sided IE?
Suggests Left-Sided IE: Recent stroke or TIA, acute onset heart failure, unexplained flank/abdominal pain (splenic/renal infarct).
Suggests Right-Sided IE: Persistent cough, dyspnea, or hemoptysis (septic pulmonary emboli), history of IV drug use or indwelling central lines.
56
This patient has acute infective endocarditis (IE), which is evidenced by severe constitutional symptoms with a rapid onset. What is the most likely underlying organism?
Staphylococcus aureus is the most common cause of acute IE in almost all groups of patients.
57
A dermatologic finding of painful subcutaneous nodules on the pads of the fingers and toes that typically develop in association with infective endocarditis. Caused by immune complex-mediated vasculitis that most likely occurs as a sequela of microthrombi occluding the vasculature.
osler nodes
58
Microabscesses with neutrophilic capillary infiltration and areas of hemorrhage caused by septic microemboli from valve vegetations
Janeway lesions
