Infective endocarditis Flashcards
How do valves open
atrium contacts
- increases the pressure inside the atrium
- Tricuspid / mitral valve open
- blood enters the ventricles
- ventricles contract pressure in the ventricles is greater than the atrium
-
How do valves work
Papillary muscles hold valves in place
- chorda tendani : yellow fibres attached to edges of valves cusps to the ventricle walls: prevents the backflow of blood
What are the function of heart valve
allows the flow of blood in one direction
- prevents backflow of blood
What are the consequence of diseased heart valve
stenosis:
- increases load on the heart
-turbulent blood flow causes thrombi
regurgitation:
- heart failure
- prothrombotic circumstances
- infective endocarditis
-
What is the foetal circulation
lungs are deflated as they would provide resistance as it would cause problems to the heart
- oxygenated blood comes from placenta
- lung circulation is by-passed
How is lung circulation is bypassed
- Foramen Ovale
- Ductus arteriosus
What is the patent foramen ovale
a hole that is between Right atrium and left atrium
- all blood is pushed into left atrium instead of the right ventricle
- shorter circuit
What is the patent ductus arteriosus
Short circuit: Communicates with pulmonary artery and aorta
Blood into pulmonary artery→ meets resistance of lungs→ bypassed directly into the aorta
What is the epidemiology congential heart diesease
more common with developmental syndomes- downs,
- more common if parent/ sibling
-
Why do congential heart disease occur?
- failure of heart to complete changes after birth
- patent ductus arteriosus
- patent formen ovale - failure of heart to develop normally
- transposition of great veins
- valve narrowing
- ventricuar septal defect
What is the consequence of patent ductus arteriosus and patent foramen ovale in babys
designed to be used with non-perfusing lung
- Interfere with perfusion of lungs
What is tetralogy of fallot
4 abnormalities:
1. Ventricular septal defect
Hole between right and left ventricle - right heart has to work harder
- Right venticular hypertrophy
additional resistance to flow of blood from stenosis
Right ventricle has to work harder→ more hypertrophic - ## Pulmonary stenosis
- Overriding aorta: aortic valve is NOT at the edge of the left ventricle more in the middle of left & righ
What is meant by ‘Eddy formation’?
Movement of fluid deviating from the general flow of a fluid
Swirling of a fluid & reverse current created by a slow turbulent blood flow
Causes coagulation of blood
Give examples for acquired valve disease
- Rheumatic heart disease
- calcification/ degeneration of heart disease
How does rheumatoid fever cause valvular heart disease
- common in developing countries
-Caused by Streptococcal A → sore throat/ pharyngitis
What are the risk favtors for s calcification of valves
- Age (1/50 over 80 years)
- Smoking
- High BP
- High cholesterol
- Obesity
What are the effects of valvular/ congenital heart disease:
Reduced pumping efficiency: resulting in”
Heart failure
Shortness of breath
Reduced exercise tolerance
Failure to thrive in childree
n
risk of heart failure
What is the tx of valve diease
Prosthetic heart valve:
- metal
- bovine valve
- cow valve
(animal is better as less co-anticoagulant requirements, better mechanically)
TAVI (Transcatheter Aortic Valve Implant)
- Require a dental assessment prior to TAVI
- Place a wire through patients femoral artery/ subclavian artery to arotic valve
Still risk of anticoagulant & risk of endocarditis
How should a pt with valve disease affect your management
risk of infective endocarditis
- risk of thrombosis/ embolism so on DOAC/ Warfarin
What are the risk factors for infective endocarditis
Structural heart disease→ cardiomyopathy / previous rheumatic fever
Prosthetic heart valve
Congenital heart disease
IVDA
Immunocompromised
Heart murmur
What are the causes of infective endocarditis
- Bacteraemia
- valve/heart abnormality or immune suppressed
- Bacterial infection of clots on valve: Vegetations (contain: fibrin, bacteria (live & dead), white cells) collect on surface of heart valves
This causes inflammation→ resulting in systemic complications
What are the clinical features of endocarditis
Fever
Rigors (shakes)
Night sweats
Malaise
Weight loss
New heart murmur or change of existing murmur
Shortness of breath
Heart failure
What is the cause of systemic complications from infective endocarditis
septic emboli:
- splinter hameorrhages
- eye
-kidney complications
- osler nodes
- janeway lesuons
- heart complications: thrombotic
where is the source of bacteraemia in infecctive endocarditiis
Instrumentation of areas with high bacterial loads
Procedures of Upper GI
Procedures of Lower GI
Procedures of Urogenital tract
Procedures of Skin
Procedures of Mouth
What are the NICE guidelines around infective endocarditis
Prophylaxis antibiotics not indicated routinely
What are SDCEP guidelines
Patients can be split into 2 groups:
1. Those that require special consideration
2. Those that don’t require special consideration
Who is a special consideration group
Previous IE
Prosthetic valve (including a transcather valve)
Patients with congenital heart disease (CHD)
What is the routine management of patients at risk of IE but no special considerations according to SDCEP
- Patient/ guardian are aware of their risk of IE
- provide advice about prevention
- Potential benefits & risks of antibiotic prophylaxis & explanation of why antibiotic prophylaxis is not recommended
- OHI
- Educate on Symptoms that indicate infective endocarditis & when to seek expert advice
- Risk of undergoing invasive procedures including non-medical procedures such body piercing/ tattooing
How do you manage pt with special considerations
TALK TO CARDIOLOGIST
1. provide prescription
2. Advise pt
3. give advice on adverse risks
4.give risks of undergoing invasive procedures
What are the risks to all patients with antibioitcs prophylaxis use
Hypersensitivity
Anaphylaxis
Resistance
C.difficle
