valvular heart disease Flashcards
valave function?
to allow forward flow but to prevent back flow
valave components?
- valave ring
- cusp
- chordea
- papillary muscles (mitral and tricuspid only)
what are chorine tendinae made from?
collagen
- attached to papillary
what are 4 different types of functional failure in valves?
- mitral stenosis
- mitral incompetence
- aortic stenosis
- aortic incompetence
stenosis?
- narrowing of the valve outlet caused by thickening of valve cusps, or increased rigidity or scarring
- cardiac output differs, increasing strain non the heart
incompetence?
insufficiency or regurgitation (which is what happens) caused by incomplete seal when valves close, allowing blood to flow backwards.
what is the first valvular heart sound?
mitral and tricuspid = systole
what is the second valvular heart sound?
aorta and pulmonary = diastole
what are common causes of cardiac valve stenosis and incompetence?
- congenital heart disease (bicuspid valve, atresia)
- cardiomyopathy (hypertrophic, dilated)
- acquired (rheumatic fever, myocardial infarction, age related (idiopathic aortic calcific stenosis, endocarditis)
what is the most common cause of damage to the heart and blood vessels?
increased turbulence
if you have aortic stenosis, what are you at risk of?
- left ventricular hypertrophy
- syncope
- sudden cardiac death
if you have pulmonary stenosis, what are you are risk of?
right ventricular hypertrophy
what are the causes of aortic stenosis?
- calcification of congenital bicuspid valve
- senile calcific degeneration
- rheumatic fevere
what are the consequences of aortic stenosis?
- increases the work of the heart
- ventricular hypertrophy
- causes cardiac failure late in clinical course
- clinical symtoms include:
dyspnoea ( breathlessness)
angina (cardiac chest pain)
syncope (collapse)
what are the causes of aortic incompetence?
- infective endocarditis
- rheumatic fever
- marfans syndrome
What are the 4 components of the valve?
- Components of valves:
1) Valve ring – fibrous ring that allows for the attachment of cusps of valves. The 4 fibrous rings are known as annulus fibrosus
2) Cusps
3) Chordae (chordae tendinea) – Chordae are the thick, strong, tendinous connections between the mitral valve and tricuspid valve cusps and the papillary muscles
4) Papillary muscles – only for mitral and tricuspid valve. Provide tensile strength to the cusps to prevent prolapse/inversion
What is the meaning of stenosis? What is the meaning of incompetence?
What are 2 other names for it?
What are the 4 most common functional failures in valves?
What are their associated murmurs?
Why are right side heart valve conditions not listed?
- Stenosis is narrowing of the valve outlet caused by thickening of valve cusps, or increased rigidity or scarring.
- Incompetence (Or insufficiency or regurgitation) is caused by an incomplete seal when valves close, allowing blood to flow backwards
- 4 most common functional failures in valves and their associated heart murmurs:
1) Mitral stenosis – high pitched early diastolic heart sound
2) Mitral incompetence – mid systolic, high-pitched sound
3) Aortic stenosis - high-pitched, “diamond shaped” crescendo-decrescendo, mid-systolic ejection murmur
4) Aortic incompetence - the typical murmur of aortic regurgitation is a soft, high-pitched, early diastolic decrescendo murmur - The same conditions occur in right side heart valves, but they are less common, and involved in less severe disease
What is infective endocarditis (IE)?
What determines the damage and severity of clinical illness from IE?
How is IE classified?
Why must be careful with subacute/chronic IE?
What are 2 clinical signs of infective endocarditis?
- Infective endocarditis (IE), also called bacterial endocarditis, is an infection caused by bacteria that enter the bloodstream and settle in the heart lining, a heart valve or a blood vessel and lead to the formation of vegetations (abnormal growths)
- The virulence (harmfulness) of organisms is what determines damage and severity of clinical illness
- IE can be classified as acute and subacute (chronic condition)
- Acute IE is caused by more virulent organisms and can lead to more severe problems quicker
- Sub-acute IE is a chronic condition caused by a less virulent organism, won’t cause a lot of problems, and can be easy to miss
- We must be careful with sub-acute/chronic IE, as patients present with fever, joint pain, splinter haemorrhages, clubbing, and it can be easy to not even consider IED
- Clinical signs of IE:
1) Splinter haemorrhages
* Clots can migrate from the affected heart valve and find their way into various parts of the body.
* If this happens in the finger, it can cause damage to the capillaries resulting in a splinter haemorrhage.
2) Clubbing
* IE causes Increases blood flow to the distal fingers, which causes tissue hypertrophy in the fingers, leading to the appearance of clubbing
What are the 3 risk factors for Infective endocarditis?
- Risk factors of infective endocarditis:
1) Valve damage
* Especially after rheumatic fever
2) Bacteraemia – presence of viable bacteria in the blood
* Can be from:
* Dental – why we are asked if we have had rheumatic fever at the dentist – procedures can be covered with antibiotics
* Catheterisation
* 10% unknown
* IV drug abuse
3) Immunosuppression
* Suppression of the body’s immune system and its ability to fight infections and other diseases
What are vegetations?
When can vegetations of the heart valve form?
How do they form?
What condition is this known as?
Are they dangerous on their own?
How can they become infected?
Why is it difficult for the immune system to deal with infected thrombotic vegetations?
- A vegetation is an abnormal growth
- Vegetations of the heart valves can form when there has been damage to the heart valves (e.g from rheumatic fever)
- Platelets and fibrin can come to try and heal this damage, leading to the formation of thrombotic vegetations (known as non-bacterial thrombotic endocarditis - NBTE)
- By itself, NBTE does not pose any particular health risk, but fragments of vegetation may break off and move towards the brain or heart, causing an embolism.
- In addition, the vegetation can provide a point of accumulation for bacteria (e.g staphylococci and streptococci) and lead to the infective form of the condition, infective endocarditis.
- When bacteria get into these thrombotic vegetations, they can grow
- It is difficult for the immune system to deal with this, as it is a point of high blood flow, making it heard for immune cells such as phagocytes to access this site
- Pieces of the vegetation can break off and cause emboli if blood blots break off and block vessels
What are 5 causes of aortic incompetence (aka regurgitation/insufficiency)?
What are 4 consequences of aortic incompetence?
- Causes of aortic incompetence (aka regurgitation/insufficiency)
1) MI
* Aortic incompetence can develop post MI due to rupture of papillary muscle
* This leads to the patient getting better post MI, and then worse
2) Infective endocarditis
3) Rheumatic fever (closely related to IE)
4) Can occur in the presence of aortic stenosis
5) Marfan’s syndrome
* Marfan’s syndrome is a genetic disorder that changes the proteins that help make healthy connective tissue.
* This leads to problems with the development of connective tissue, which supports the bones, muscles, organs, and tissues in your body.
* Leads to valves being floppy
- Consequences of aortic incompetence:
1) Increases volume of blood to be pumped significantly
2) Increases the work of the heart
3) Cardiac hypertrophy
4) Cardiac failure
What are 4 causes of mitral incompetence?
What are 2 consequences of mitral incompetence?
- Cause of mitral incompetence is cusp damage from:
1) Rheumatic heart disease – scarring
2) Floppy valve – stretch
3) Marfan’s syndrome – affects connective tissue formation
4) Infective endocarditis – perforation (hole made) - Consequences of mitral incompetence:
1) Pulmonary hypertension- blood going back into pulmonary circulation, which increases pressure
2) Right ventricular hypertrophy – heart has to pump more blood to keep up with back flow
