Infectious and Valve Disease Flashcards
Valvular stenosis and valvular regurgitation and what are their different types
Stenosis is the thickening of the valve or the failure of the valve to open completely whereas regurgitation is the failure of the valve to close completely
Valvular insufficiency is also regurgitations
Can be pure, like it can be either stenosis or insufficiency or it can be isolated or combined which basically means it involves more than one valves
Different mitral valve and aortic valve diseases and their associated reasons
Mitral valve stenosis - the only reason for that is rheumatic fever
Mitral valve regurgitation has several causes - one of the cause is mitral valve prolapse which is fairly common in women
Aortic stenosis - rheumatic heart disease and you can also have calcification
Calcific stenosis - this valve is fused due to the white Ca deposits, this is the tricuspid valve
Bicuspid or mitral valve - Calcific Stenosis
Calcific Stenosis
Facts about mitral valve prolapse
- 20% among women, fairly common.
- Myxamatous degeneration
- Echo can find it, there is a chance of sudden death due to valve not closing properly causing arrythmias
Remember this is part of the mitral valve regurgitation
Acute Rheumatic Fever
- It mainly happens in children, following a pharyngeal infection which causes the inflammation of the valve of the heart leading to their defective function
- It is due to autoimmune disease due to streptococcus pyogenes antigens - molecular mimicry
What is the name of the criteria for Rheumatic fever
It is called the Jones criteria, it consist of mythralgia, acute phase reactants and fever
What are the symptoms of Rheumatic fever
- There are distinct foci of fibrinoid necrosis of lymphocytes and macrophages which are called the ASCHOFF BODIES. Aschoff bodies are the defining symptoms of rheumatic fever, it is found in all layers of the heart.
- Non specific arthritis - migratory arthritis
- Erythema Maginatum - subcutaneous nodules of aschoff bodies
Chronic inflammation of the valves in rheumatic fever, usually mitral valve is affected the most but aortic valve can also be affected.
What are the pathophysiological changes that take place in the heart in ARF
- Fibrous adhesions can cause fusion of the leaflets of the mitral valve
- Shortening, thickening and fusion of chordae tendenae
- Dilation of left atrium that can cause arrythmias
- Thrombosis of the left atrium
- Bacterial endocarditis
What is the end results of rheumatic fever
It leads to Rheumatic Heart Disease (RHD), this mainy happens due to mitral stenosis, blood is gonna get backed up in the lungs:
- Pulmonary congestion and edema
- Right ventricle hypertrophy and right side heart failure
- Hemorrhage and infarction
- Hyperplasia of the pulmonary arterioles
Mitral valve stenosis, its called the fish mouth
Aortic valve stenosis, fusion fo the aortic valve leaflets due to RF or RHD
Endocarditis and what is the pathological criteria
Acute or Sub acute bacterial endocarditis, SABE or ABE. He listed a whole range of risk factors:
RHD is one of them
Pathological criteria is microorganisms in the blood and histological evidence of endocarditis in vegetation or in intracardiac abscess
What is the clinical criteria for endocarditis
Major: 1. Positive blood culture
- Evidence in on echocardiogram
- New valvular regurgitation
Minor: IV drug use, fever, Janeway lesions,Osler nodes and Roth spots
Contaminants of blood cultures
These contaminants are there when you puncture the skin to take blood samples and these microorganisms enter the blood sample from the top surface of the punctured skin
Staph spp, Bacillus spp, Coryneabacterium spp and Propionoibacterium spp
Contaminants = misinformation
What are some of the other causes for contaminants in blood sample
- Povidone-iodine solution can be contaminated which is used to sterilize the skin
- Residents of med students dont wait for the iodine to dry on the skin - most common cause, have to wait 60 s!
- Collection vials can be contaminated
- Drawing culture from indwelling catheter, sample from another site should also be collected
What is an effective way to get avoid the contaminants when getting blood sample
Take samples from 2 different poisitions in the body and follow proper procedure (wait for the iodine to dry out)
What pathogen is the leading cause of endocarditis
Staphylococcus aureus, it is a very pathogenic microorganism, it can even infect a normal valve, usually a valve has to be defective to get infected, it is called aureus (gold) cuz it appears yellow on the blood culutre plate.
It leads to large vegetations that almost always cause murmurs
Staph aureus caused endocarditis, it can be seen that it has eaten through the valve
Staph aureus can break off from the valve and travel downstream, causing infection
What are HACEK
Just need to remember that cultures for these organisms have to be held for longer than 30 days, need to talk to ID to get approval for that
What are the cardiac complications of Infectious Endocarditis
Perforation of ventricular septum and valvular insufficiency and/or stenosis
Supurative pericarditis
Dehiscene of an artificial valve since the pus causes the sutures to break
There are embolic complications as well
