Endocarditis Flashcards
Pathologies of endocarditis
Prototypic Native Valve Endocarditis (NVE) lesion
Non-bacterial Thrombotic Endocarditis (NBTE)
What are NVE lesions made up of?
Mass of platelets, fibrin, microbial microcolonies with scant inflammatory cells
What are NBTE (AKA marantic endocarditis) made up of?
uninfected platelet-fibrin thrombus often a nidus for mocrobial adhesion during bacteremia
Explain the Venturi effect
NBTE and NVE develop on sides of low-pressure sink just beyond the valve or intraventricular defect or stenosis (they glob on)
T/F Cardiac valves have no dedicated blood supply?
T
What effects does the lack of dedicated blood supply have on cardiac valves?
Host immune response blunted
Limited access of abx
What cardiac locations are involved in endocarditis?
Native/prosthetic valves
Low-pressure side of ventricular septal deffect
Mural endocardium damaged by aberrant jets
Intracardiac devices
What are the 2 older terms still used in some places to classify endocarditis?
Subacute Bacterial Endocarditis (SBE)
Acute Bacterial Endocarditis
What is the classification system now preferred for endocarditis?
Incubation classification
Incubation less than about_____ is considered short incubation?
Six weeks
Inbuation greater than about ______ is considered long incubation?
Six weeks
What are the most common current etiologies of endocarditis?
Congenital heard disease Illicit IV drug use Degenerative Valve dz Intracardiac devices Incidence notability increased in elderly
What percent of cases of NVE are related to healthcare?
30-35%
What percentage of endocarditis involves prostehtic valves?
16-30%
during what time period is a patient with a valve replacement at greatest risk of endocarditis?
6-12 months
What locations on the body can serve as possible soures of infective endocarditis?
Oral cavity skin upper respiratory tract GI GU
What bacteria may result in endocarditis from oral cavity, skin, and upper respiratory tract?
Strep Viridans
Staphlococci
HACEK
What bacteria may result in endocarditis from GI source?
Strep gallolyticus
Polyps
colon tumors
What bacteria may result in endocarditis from a GU source?
Enterococci
What bacteria may result in endocarditis from a nosocomial source?
Staph aureus
CoNS (coag neg staph)
Enterococci
What procedures may result in procedure induced bacteremia?
Endoscopy Colonoscopy Barium enema Dental Extractions!!! Transurethral resection of prostate (TURP) TEE
What is the timeline for recognizing a nosocomial infective endocarditis?
Exposure within 90 days
What valve is most commonly involved in endocarditis in an IV drug user? And what pathogens are most common?
Tricuspid-S. aureus, commonly MRSA
What percentage of patient’s have negative blood cultures? What is this due to?
5-15% come back negative (33-50% of this is due to premature initiation of tx.)
Pathogenesis of E-carditis (4)
- Adhesion molecules recognize MSCRAMMS
- Platelet-fibrin vegetations form dense microcolonies of microbes
- Organisms deep inside the vegetations are inactive and resistant
- Surface organisms continuously shed into the blood stream
It is the result of ___________ that causes the symptoms of Endocarditis?
Fighting the infection
What symptoms result from the pathophys of endocarditis?
Constitutional - cytokine production Damage to intracardiac structure Embolization of veg fragments - leading to infection or infarction Bacteremia Tissue injury
cadiac presentation of E-card?
murmurs may not start right away but occur eventually in 85%
CHF (30-40%)-from valvular dysfunction
Intracardiac fistula
MI-dt emboli (2%)
Classic presentation seen in 50% of endocarditis pt’s?
Petechiae subungual (splinter) hemorrhages Osler nodes Janeway lesions Roth spots
Define Osler nodes
Tender subcutaneous nodules usually distal pads of the digits
Define Janeway Lesions
Nontender maculae on palms and soles
Define Roth spots
Retinal hemorrhages w/ small clear centers (rare)
CNS diseases that can present with endocarditis?
Embolic stroke
Intracerebral hemorrhage
Multiple microabcesses
Seizures
What might be seen on CXR in a patient with septic pulmonary emboli?
solid and cavitary lesions “circles of crud”
What might be seen on EKG secondary to IE?
Complete heart block-dissociation
Signs of IE?
Splenomegaly stiff neck delirium paralysis, hemi, aphasia conjunctival hemorrhage pallor gallops rales cardiac arrhythmia pericardial rub pleural friction rub subacute native valve endocarditis
What are the signs of subacute native valve endocarditis?
Low grade fever anorexia weight loss flu-like symptoms polymyalgia-like syndromes pleuritic pain syndromes similar to rheumatic fever abd. symptoms (ruq pain, vomiting, postprandial distress)
What are Most common pathogens of IE?
Staph aureus (MC)
CoNS
Gram negative bacilli
**remember the culture can come back negative in many patients
What is the test of choice for a pt with endocarditis?
ECHO (TEE GOLD!!!)
What is true about the risk of doing a TTE on a pt?
TEE carries a risk of providing a source for Endocarditis.
Duke’s criteria for definite Endocarditis
2 major criteria
1 major and 3 minor
or 5 minor
Duke’s criteria for possible endocarditis
1 major and 1 minor
or 3 minor
Major criteria for Dukes:
Positive blood culture
Positive Echo
Minor criteria for Dukes:
Predisposition Fever Vascular phenomena Immunologic phenomena (Roth's spots etc.) Microbiological evidence
What are we looking for on Echo?
Vegetation
Indications for REQUIRED surgical intervention for pt’s with endocarditis?
Mod to severe CHF
Partially dehisced unstable prosthetic valve
Persistant bacteremia despite ABX
Lack of effective microbial tx (fungal)
S. Aureus prosthetic valve with intracardiac complication (Fistula)
Relaphse after optimal abx. tx.
Once surgery is decided upon what indications require that surgery to be done EMERGENTLY (same day)
Acute aortic regurgitation plus pre-closure of mitral valve
Sinus of valsalva abscess ruptured into R heart
Rupture of pericardial sac
What patients must have prophylaxis prior to dental procedures?
Prosthetic heart valves
Prior endocarditis
Unrepaired cyanotic congenital heart disease
completely repaired congenital heart defects during 6mos after repair
Incompletely repaired congenital heart disease w/ residual defects adjacent to prosthetic material
(valvulopathy developing after cardiac transplantation-this is changing and less necessary)
What is the standard oral regiment of abx prophylaxis for pt’s who require it prior to dental procedures?
Amoxicillin: 2 g PO 1 h before procedure
If left untreated what is the mortality of IE?
14.5%
What increases the mortality rate for IE?
Increased age Involvement of Aortic Valve CHF CNS complications Underlying chronic medical conditions e.g. DM Rates vary dependent upon microbe
