infective endocarditis Flashcards
etiology of infective endocarditis ?
acute IE - fatal within 6 weeks
staph aureus
risk factors : IV drug user, prosthetic valves , pacemaker , Implanted cardioverter defibrillator
affects - healthy valves
============== subacute IE strep viridian's risk factors - predamaged native valves - mainly mitral dental procedures
staph epidermis
risk factors - infected peripheral venous catheters
common in PROSTHETIC HEART VALVES, pacemakers , ICD
enterococci - est enterococci faecalis
affects NATIVE VALES and PROSTHETIC
risk factor - NOSOCOMICAL following gastrointestinal and genitourinary procedures
strep gallolyticus
affects NATIVE VALVE
risk factor - Colorectal cancer
gram negative HACEK - Haemophilus species
affects NATIVE VALVES
risk factor - poor dental hygiene or periodontal infection
=========
fungal - CANDIDA , APERGILLUS FUMIGATUS
affects NATIVE VALVES
risk factors - immunocompromised or suppressed
IV drug abuser
cardio surgical interventions
what is the disadvantage of enterococci ?
multiple drug resistance
what are the risk factors for infective endocarditis ?
male
age over 60
cardiac conditions
acquired valvular disease - rheumatic heart disease , aortic stenosis
prosthetic heart valves
congenital heart defect
non cardiac risk factors poor dental status dental procedures IV drug uses intravascular devices
what are the cardiac clinical features of infective endocarditis ?
fever , chills and acycardia
tiredness , weight loss , night sweats
dyspnea
pleuritic chest pain
=====
DEVELOPMENTS OF NEW HEART MURMUR - tricuspid valve regurgitation - HOLOSYSTOLIC - loud at left sternal border in IV drug users , immunocompromised congenital heart diseases central venous catheters
aortic valve regurgitation - early diastolic murmur - loudest at left sternal border
mitral valve regurgitation - HOLOSYTOLIC MURMUR - loudest at heart’s apex and radiates to left axilla
=============
Heart failure - due to valve insufficiency
dyspnea
low limb edema
==========
Extracardiac manifestations
common in left sided IE
exception of pulmonary embolic manifestation which are common in right sided IE
what are the extra cardiac manifestation
petechiae - especially splinter hemorrhages underneath the finger nails
septic micro emboli
janeway lesions
Small, nontender, erythematous macules on palms and soles
Microabscesses
Osler nodes: painful nodules on pads of the fingers and toes caused by immune complex deposition
Roth spots: round retinal hemorrhages
Acute renal injury
Including hematuria and anuria
Due to renal artery occlusion or glomerulonephritis
Splenomegaly and possible LUQ pain
Due to splenic artery occlusion or splenic abscess
May lead to splenic rupture
Neurological manifestations (e.g., seizures, paresis): due to septic embolic stroke,
Distinguishing clinical features of Right-sided endocarditis
Bacterial thromboemboli to pulmonary vasculature
Clinical features of right heart failure (e.g., peripheral pitting edema, abdominal pain from hepatic congestion
Right-sided endocarditis is due to ?
Affected valves
tricuspid and pulmonic valve
associated with venous instrumentation (e.g., IV drug use, indwelling venous catheters)
Main pathogens
S. aureus (MSSA more often than MRSA)
Streptococci
Left-sided endocarditis is due to ?
Main pathogens :
S. aureus
Viridans group streptococci
what is the diagnosis of infective endocarditis
The modified Duke criteria help categorize the diagnostic likelihood of IE: definite vs. possible vs. rejected.
All patients should receive multiple blood cultures and echocardiography.
===========
Major
Prior to treatment: 3 sets from different venipuncture sites
Typical organisms from 2 separate blood cultures
≥ 2 positive blood cultures drawn > 12 hours apart
Characteristic echocardiographic findings of IE
Hyperechoic mobile masses located on the valve, mural endocardium, or prosthetic material
Abscess (e.g., perivalvular abscess)
New valvular regurgitation (especially with valve prolapse, perforation, or destruction)
Prosthetic valve dehiscence
=========
minor
Predisposing condition (e.g., underlying heart abnormality, IV drug use) Fever > 38°C
Vascular abnormalities - laneway lesions
Immunologic phenomena - Glomerulonephritis, Osler nodes, Roth spots, positive rheumatoid factor
Microbiology: positive blood cultures not fulfilling major criteria or serological evidence of infection with common organisms
=========
pathology criteria
Microorganisms demonstrated by tissue culture or histology
Characteristic histologic features of active endocarditis
from the dukes criteria what can you interpret ?
Definite IE if any of the following are present:
≥ 2 major criteria
≥ 1 major criterion PLUS ≥ 3 minor criteria
≥ 5 minor criteria
≥ 1 pathological criterion
=======
possible IE
≥ 1 major criterion PLUS ≥ 1 minor criterion
≥ 3 minor criteria
management of infective endocarditis ?
A-E
blood culture
monitoring 2 sets ever 24-48 hr until clearance
Consult infectious diseases (ID) early to plan treatment and evaluate the need for empiric therapy
treatment for infective endocarditis should not be commenced before a d
antibiotics as soon as blood cultures are taken
emperic therapy
Identify patients requiring surgery consult (e.g., prosthetic valve endocarditis).
=========
empiric antibiotics
Indicated for hemodynamically unstable patients
with acute symptoms and/or complications
Common regimens (These frequently include drugs that have significant side effects ., AKI, ototoxicity)
Native valve endocarditis acute : vancomycin PLUS ceftriaxone / cefepime
Subacute bacterial endocarditis (weeks) :
Vancomycin
PLUS ampicillin-sulbactam
Prosthetic valve endocarditis: vancomycin + gentamicin PLUS rifampin PLUS cefepim (if ≤ 1 year after placement)
> 1 year after valve placement
Vancomycin
PLUS ceftriaxone
=========
Targeted antibiotics
Staphylococci
Methicillin-susceptible staphylococci - nafcillin, oxacillin
Methicillin-resistant staphylococci (e.g. MRSA: vancomycin
Prosthetic valve endocarditis (≤ 1 year after placement): add gentamicin PLUS rifampin to regimen
strep viriiddans - benzylpenicillin or penicillin G / amoxicillin + gentamicin
Enterococci: combination therapy (e.g., ampicillin PLUS gentamicin)
HACEK: ceftriaxone (first-line)
============
SURGERY
Indications for surgical consultation include: Prosthetic valve endocarditis Valve dysfunction Signs/symptoms of heart failure New heart block
Options: valve replacement or valve repair
