Infective Endocarditis Flashcards
What are the 3 layers of the heart wall?
- Epicardium
- Myocardium
- Endocardium
What is another name for the epicardium?
Visceral pericardium
Which heart layer makes up the majority of the heart mass?
Myocardium
What heart layer lines the chambers, valves, and vessels?
Endocardium
What is the severity of infective endocarditis? What does this vary on?
Indolent illness that responds to antibiotics to life-threatening
Depends on infecting organism
How does IE occur?
- Bacteria enters bloodstream and lodges onto heart valve, especially one with prior damage or turbulent blood flow
What is the etiology of infectious endocarditis?
- Oral source
- IV drug use
- EGD
- Colonoscopy
- TURP
- IV catheters
What are possible oral sources of infectious endocarditis?
- Dental extraction
- Periodontal surgery
- Tooth brushing
- Chewing candy
What determines the location of infection?
- Production of turbulent blood flow
- Left-sided IE is more common, except among IVDU
What is the most common organism that causes native valve endocarditis?
- Staph aureus followed by streptococcus
What are valve/heart disorders that increase risk of IE?
- Rheumatic valvular disease
- Congenital heart disease- PDA, VSD, tetralogy of Fallot
- MVP with MR
- Degenerative heart disease, AS due to bicuspid AV, Marfan syndrome
What organisms are most common in early prosthetic valve endocarditis (within 2 months)? Late?
- Staphylococci (within 2 months)
- Streptococci
What are the most common causative organisms of IV drug user endocarditis?
- Staph aureus (MC)
- streptococci and enterococci
Which valve is most commonly impacted by IV drug user endocarditis?
Tricuspid valve
What are leading causes of nosocomial/healthcare-associated endocarditis?
- Central and peripheral IV catheters
- Pacemakers and ICDs
- HD shunts
- Permacaths
What are the most common pathogens responsible for nosocomial/healthcare-associated endocarditis?
- Gram-postive cocci, such as S. aureus, enterococci, nonenterococci streptococci
Who more commonly gets fungal endocarditis?
- IV DU and ICU patients who receive broad spectrum abx
What are risk factors for endocarditis?
Cardiac
* Previous endocarditis
* Prosthetic valve or pacemaker
* Valvular or congenital heart disease
Noncardiac
* IV DU
* IV catheter
* Immunosuppression
* Recent dental or surgical procedure
What are complications of endocarditis?
- Rupture of valve tissue or chordal structures leading to valvular regurgitation
- Vegetation obstructing valve orifice or creating embolus
- Conduction system impacted by myocardial abscess
- Infection invading interventricular septum causing intramyocardial abscesses or septal rupture
- Septic systemic and pulmonary emboli possible
What is the MC cause of death in patients with IE?
Heart failure
What are symptoms of IE?
- Symptoms within 2 weeks of precipitating event or minimal for 6 months
- Symptoms related to systemic infection, emboli, or other complications, such as CHF
- FEVER (90% of IE)
- MC complaints: fever, chills, weakness, shortness of breath, night sweats, loss of appetite and weight loss
- Musculoskeletal symptoms, such as back pain
What conditions are often present due to IE?
- Heart murmurs (>80%)
- CHF (2/3)
- Septic emboli
Which etiology of endocarditis has less heart murmurs?
IVDU with TV endocarditis (1/3 of time)
What would a pulmonary emboli due to IE look like?
- pleuritic chest pain
- cough with blood-tinged sputum
- cavitating lesions on chest x-ray
septic embolic can travel through the systemic system to what arteries with IE?
- Renal
- Cerebral
- Coronary
- Mesenteric
What are physical findings of peripheral manifestations of IE?
- Petechiae
- Splinter hemorrhages
- Janeway lesions
- Osler nodes
- Roth spots
How do petechiae in IE present? What organisms are common causes of this?
- Red, non blanching lesions in crops on conjunctiva, buccal mucosa, palate, extremities
- Strep and staph
What are splinter hemorrhages? What organisms are common causes?
- Linear, red-brown streaks in nail beds
- Strep and staph
What are Janeway lesions? What is a common cause?
- Erythematous/hemorrhagic macular or nodular, painless patches on palms or soles caused by emboli
- Staph
What are Osler nodes? What is a common cause?
- Painful nodules on pads of fingers or toes caused by vasculitis
- Strep
What are roth spots? What organism is a common cause?
- Oval, pale retinal lesions surrounded by hemorrhage
- Strep
What is one of the most serious complications of IE?
- CNS embolization
If you see a young patient with a CVA, what needs to be in DDx?
IE
What is the clinical presentation of neurologic manifestations of IE (CNS embolization)?
- Headache or seizures
- Toxic encephalopathy
- Meningocephalitis
What should your initial work-up for IE include?
CBC and blood cultures
What are often results of CBC in IE?
Anemia
What nonspecific abnormal tests can be present in IE?
- Anemia on CBC
- Elevated ESR, CRP, LDH, lactic acid
- UA with proteinuria and hematuria
How should blood cultures be performed to test for bacteremia in IE?
- Should be obtained prior to initiation of antibiotics
- At least 3 sets of blood cultures from different venipuncture sites, with the first and last samples drawn at least an hour apart
What might cause a negative blood culture even with bacteremia?
- Previous antibiotics
- Fastidious organisms such as Legionella, Bartonella, Chlamydia, or fungi
What test is recommended in all cases of suspected IE?
- Echocardiography
- TTE may be sufficient or may need TEE for small vegetations or large body habitus
Why would transesophageal echocardiography be done first?
- Prosthetic vavles
- implantable cardiac device
- prior valve abnormalities
- obese or chest-wall deformity
What are major Duke criteria for diagnosis of IE?
- Positive blood culture for IE: typical organisms, 2 or more positive cultures
- Evidence of endocardial involvement on echo
- New regurgitant murmur
What would be evidence of endocardial involvement on echo?
- intracardiac mass on a valve or supporting structure
- myocardial abscess
- partial dehiscence of a prosthetic valve
What is minor Duke criteria for diagnosis of IE?
- Predisposing heart condition or IVDU
- Fever (>38 or >100.4)
- Vascular and embolic phenomena
- Immunologic phenomena
- Microbiologic evidence
What is included in Duke criteria for vascular and embolic phenomena?
- major arterial emboli
- septic pulmonary infarcts
- mycotic aneurysm
- intracranial hemorrhage
- conjunctival hemorrhage
- Janeway lesions
What are immunologic phenomena in Duke criteria?
- Glomerulonephritis
- Osler nodes
- Roth spots
- Rheumatoid factor
What is considered microbiologic evidence in Duke criteria?
- Single positive blood culture or serologic evidence of active infection with typical organism
What can be interpreted as a definitive IE based on Duke Criteria?
- 2 major criteria
- 1 major and 3 minor
- 5 minor
What can be interpreted as possible IE based on Duke Criteria?
- 1 major and 1 minor
- 3 minor
How are IE patients managed?
- Antibiotic therapy
- Management of CHF
- Management of systemic/pulmonary sequelae
- Surgery
How long should a patient be on antibiotic therapy for IE?
Usually 4-6 weeks
What antibiotics should be given for native valve IE?
- Pen G and gentamicin
- MRSA and penicillin-resistent strep: vancomycin
What antibiotics should be given for IVDU IE?
- Nafcillin
- Gentamicin
- Vancomycin
What antibiotics should be given for prosthetic valve IE?
- Vancomycin
- Gentamicin
- Rifampin
After empiric therapy, what should antibiotic choice be based on?
- blood or pathology culture results
How is fungal IE treated?
- Amphotericin B
- Surgery for definitive management
How is surgery performed for IE?
- Open sternotomy valve replacement, repair, or debridgement
- Do not delay surgery for antibiotic therapy (prosthetic valve IE rarely occurs) if patient is hemodynamically stable
What are surgery indications for IE?
- CHF refractory to standard medical therapy
- Fungal IE
- Persistent sepsis after 72 hours of appropriate abx therapy
- Recurrent septic emboli, especially after 2 weeks of abx
- Ruprute of aneurysm of the sinus of Valsalva
- Conduction disturbances caused by septal abscess
- Kissing infection of anterior mitral leaflet in patients with IE of aortic valve
Patients who are diagnosed with with IE and inpatient should be thoroughly evaluated by who?
Dentist
What should a dental examination include?
- Focus on periodontal inflammation and pocketing around teeth, caries
- Intraoral radiographs when patient is stable
How much of IE cases are a consequence of invasive procedures that produce a significant bacteremia?
15-25%
What is endocarditis prophylaxis?
- Good oral hygiene
- Amoxicillin 30-60 min prior to procedure
What is the most common source of spontaneous bacteremias?
Gingivitis
Who should recieve antibiotic prophylaxis?
Patients at high risk for IE undergoing procedures that have high likelihood of bacteremia
Which patients are considered at risk for IE?
- Prosthetic heart valves
- Prior endocarditis
- Cyanotic congenital heart disease
- Cardiac transplantation recipients who developed cardiac valvulopathy
Which procedures require endocarditis prophylaxis for patients at risk?
- Any procedure involving manipulation of gingival tissue or periapical region of teeth, or perforation of oral mucosa
- Tonsillectomy or adenoidectomy
- Invasive procedures involving incision of the respiratory mucosa
- Procedures on infected skin or musculoskeletal tissue including I&D of abscess
No longer recommended for GI or GU procedures
What dental procedures require antibiotic prophylaxis in at risk patients?
- Extraction
- Routine cleaning
- Scaling and root planing
- Periapical root canal treatment
- Fitting orthodontic bands
- Placing subgingival medications
- Biopsy
- Suture removal
What antibiotics are used for endocarditis prophylaxis if allergic to penicillin?
- Clindamycin
- Cephalexin
- Azithromycin
What antibiotics are used for endocarditis prophylaxis if unable to take PO?
- Ampicillin
- If allergic to penicillin: Cefazolin or ceftriaxone, or clindamycin
Recap: In infective endocarditis, what happens first that allows for bacteria to adhere and form vegetations?
- Damage or injury to heart valves
Recap: who should infective endocarditis be suspected in?
- Individuals with fever and risk factors like presence of prosthetic valve or cardiac device, IVDU, immunosuppression, or a recent dental or surgical procedure
Recap: how is infectious endocarditis diagnosed?
- According to Duke’s criteria
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Recap: how is infectious endocarditis treated?
- High doses of IV antibiotics for 6 weeks to maximize diffusion into vegetation
- Some individuals need surgical debridement of infected material and replacement of the valve with artificial heart valve
Recap: What would you use if antibiotic prophylaxis is recommended?
Amoxicillin orally or ampicillin IV or IM one hour before procedure
- A 34 year old woman was recently hospitalized for appendicitis and comes to the emergency department because of a 4-day fever. In addition, she reports painful bumps that appeared on her foot earlier this morning. The patient admits to recent weight loss and denies recent travel or sick contacts. You find a new regurgitant murmur and micro-splinter hemorrhages. Blood cultures are positive for bacteremia. Which of the following is the most likely potential complication as a result of the patient’s condition?
1. Aortic Dissection
2. Bronchitis
3. Deep vein thrombosis
4. Heart Failure
5. Osteoporosis
- Heart Failure
A 45 year old homeless male presents to the emergency department with fever, chills, shortness of breath, and cough of 4-days duration. The patient reports he has also noticed several new skin lesions that were not present before, some of which are painful to the touch. The patient uses IV heoin and reports he last used heroin yesterday.
Temperature is 101.6, HR 106/min, RR 24/min, BP 100/62
PE: disheveled. Erythematous lesions on chest, arms, and hands some painful to palpation. Ecchymotic lesions of upper nail beds. Rales in lungs bilaterally and a holosystolic murmur at left lower sternal border.
Which of the following clinical features is required for the diagnosis of the patient’s condition?
- Fever
- Non painful erythematous lesions
- Evidence of valvular regurgitation
- Nail bed hemorrhage
- Evidence of valvular regurgitation
What is the MC organism to cause IE in IV drug users?
Staph aureus
What is the MC valve involved in IV DU endocarditis?
Tricuspid
65 year old man with history of bicuspid and aortic valve replacements comes to ED because of 1-week history of fever and chills. Denies recent cough, sinus congestion or drainage, night sweats, weight changes, recent travel, or sick contacts.
PE: febrile with bilateral lower extremity petechial rashes. 4/6 systolic ejection murmur and lung sounds normal on auscultation. No neurological deficits and remainder of physical exam unremarkable. What is most appropriate first step in management of patient?
CBC and blood cultures
