Endocarditis Flashcards
What is bacteriemia?
Bacteraemia is presence of bacteria in the blood - blood is usually sterile, so bacteraemia could result in sepsis.
What is endocarditis?
Inflammation of the inner lining of valves of the heart (usually mitral and aortic), the endocardium.
What is the epidemiology of infective endocarditis?
Usually older than 50
25% mortality
Maybe acute or subacute
What are the risk factors for developing endocarditis?
Heart valve abnormalities such as congenital herat disease, calcification of valves (elderly patients)
Having prosthetic valves
Being an IV drug user or using IV lines
Describe the pathogenesis of infective endocarditis
First step is damage to the heart valve.
This results in turbulent blood flow over the endothelium, leads to platelet and fibrin deposition.
Transient bacteraemia -> organisms settling into the valve set up. They live there creating a microbial vegetation.
Consequences of infective endocarditis?
Microbial vegetations can break off, becoming lodged in a capillary bed.
This can lead to abscess formation or haemorrhage - FATAL!
What are the common causative organisms of endocarditis?
Staph aureous - most common. From the mouth and causes bacteaemia through dental treatment.
Viridans are almost as common as staph A. They also live in the mouth.
What are some atypical gram negative organisms that cause endocarditis?
HACEK Haemophilus Agreggibacter Cardiobacterium Eikenella Kingella
What is the major criteria for diagnosing infective endocarditis?
1) Two seperate positive blood cultures for microorganisms typical for IE.
2) Echocardiographic evidence of endocardial involvement
3) New valvular regurgitation
What is the minor criteria for diagnosing infective endocarditis?
Pyrexial
Predisposition (i.e. heart condition or IV use)
Vascular evidence such as major emboli (from vegetation, haemorrhage, janeway lesions, oslers nodes
Some sort of microbio evidence - positive blood culture doesn’t meet major criteria, or positive serology consistent with IE typical organisms
What is the significance of Staphylococcus Epidermidis in blood cultures?
Could be contaminant from skin (when taking sample!)
Could be from IV drug users or prosthetic valves/joints
Take another set of blood culture to confirm!!!
What is the appearance of staph aureous?
Clusters of cocci, gram positive (stain purple)
What tests should be performed to determine strain/microorganism?
Use media to create colony
Use MALDI TOF profile spectrum to identify species.
What is the clinical presentation of acute IE?
Overwhelming sepsis and cardiac failure (heart unable to pump blood to match body’s needs)
What are the symptoms of subacute IE?
Fever Malaise Weight loss Tiredness Breathlessnes
What are the signs of subacute IE?
Fever New or changing heart murmur Finger clubbing Splenomegaly Roth spots, Janeway lesions, Oslers nodes, Splinter haemorrhages Microscopic blood in urine (haematuria)
What is the appearance of Streptococci viridans?
Alpha hemolytic on blood agar, gram positive stain - purple
What are the different types of prosthetic valve endocarditis?
Early - infected before insertion, usually due to Staph aureus or Staph epidermidis. Presents within 60 days
Late- Due to coincidental bactereamia (turbulent blood flow due to unnatural valve)
Treatment for patients with prosthetic valves and infective endocarditis?
Vancomycin IV IMMEDIATE Gentamicin IV IMMEDIATE Rifamicin PO DELAYED (3-5 days) Often valve replacement required. Treat with VGR!
What is the microrganism usually found in people who inject drugs?
Usually staphylococcus aureus
Found in right side of heart, likely to find pulmonary septic emboli
What is the treatment for people who inject drugs?
Flucloxacillin IV - Staph aureus is gram positive
What is the treatment for native valve endocarditis?
Amoxicillin and gentamicin IV
endocarditis makes me go AG!
What is the treatment for staphyloccus epidermis infection?
Vancomycin IV IMMEDIATE Gentamicin IV IMMEDIATE Rifamicin PO DELAYED (3-5 days) Often valve replacement required. Treat with VGR!
What is the treatment for staphylococcus aureus?
Fluclxacillin IV
Monitoring guidelines for IE..
IV antibiotics for 4-6 weeks
Monitor cardiac function, temperature and CRP
If failing antibiotic therapy consider referral for surgery early! Espiecally if there is high embolic risk or high heart failure risk!
What is myocarditis?
Inflammation of heart muscle. More common in young people, cause of sudden death.
What are the symptoms of myocarditis?
Fever
Chest pain
shortness of breath
Palpitations
What are the signs of myocarditis
Arrythmia
Cardiac failure
How is myocarditis diagnosed?
Sample from throat swab and stools
PCR confirms viral presence
What is the most likely causative microorganism family for myocarditis?
Enteroviruses. Results in apoptosis and necrosis of muscle tissue. Prognosis is either resolving infection or ongoing autoimmune response - this leads to dilated cardiomyopathy.
What is pericarditis?
Inflammation of pericardium (visceral serous and fibrous.) Often occurs with myocarditis.
What is the cause of pericarditis?
Usually viral
Bacterial less common but can occur following cardiothoracic surgery. RARELY secondary to endocarditis or pneumonia.
What is the treatment for viral aetiologies?
Viral aetiology - peri and myocarditis
Supportive treatment
What is the treatment for bacterial pericarditis?
Antibiotics and drainage
