Valvular Heart Disease Flashcards
What percentage of heart failure involves valve disease?
10%
What is essentially the function of the valves?
To allow forward flow, but to prevent back flow
What are the 4 components of the mitral and tricuspid valves?
Cusps
Papillary muscles
Chordae tendinieae
Valve ring
There are 8 types of failure in valves, 2 potentials for each valve. List all 8, stating which are more likely to occur.
Mitral stenosis
Mitral incompetence
Aortic stenosis
Aortic incompetence
(above are more likely and more severe than those below)
Tricuspid stenosis
Tricuspid incompetence
Pulmonary stenosis
Pulmonary incompetence
Define stenosis in reference to valvular heart disease.
Narrowing of the valve outlet caused by thickening of valve cusps, or increased rigidity or scarring
Define incompetence in reference to valvular heart disease.
Aka insufficiency or regurgitation (which is what happens).
Caused by incomplete seal when vales close, allowing blood to flow backwards.
What is a direct result of stenosis?
Hypertrophy, but not hypertension (due to reduced blood flow)
What is a direct result of incompetence?
Higher systolic pressure, but lower diastolic pressure
What is a vegetation?
Arterial thrombus (platelets, fibrin and more platelets)
What causes the first heart sound?
Both mitral and tricuspid valves closing (start of systole)
What causes the second heart sound?
Both aortic and pulmonary valves closing (start of diastole)
What are some common causes of valvular stenosis and incompetence?
Congenital heart disease Cardiomyopathy Acquired: - Rheumatic fever - MI - Age related - Endocarditis
What are 3 causes of aortic stenosis?
Calcification of congenital mitral valve
Senile calcific degeneration
Rheumatic fever
What are some consequences of aortic stenosis?
o Increases work of the heart
o Ventricular hypertrophy
o Causes cardiac failure late in the clinical course
o Fibrous tissue calcification
o Can lead to right ventricular hypertrophy
What are some associated clinical symptoms and signs of aortic stenosis?
o Dyspnoea (breathlessness) o Angina (cardiac chest pain) o Syncope (collapse)
What are 3 causes of aortic incompetence?
Marfan’s syndrome
Rheumatic fever
Infective endocarditis
Why can aortic incompetence or regurgitation lead to cardiac hypertrophy or even cardiac failure?
There is an increase in the volume of blood that needs to be pumped (to compensate for blood leaking back into the ventricle) –> increased workload of the heart –> left ventricular hypertrophy –> left cardiac failure
What can cause mitral incompetence?
Rheumatic fever
Infective endocarditis
Floppy valve & Marfan’s syndrome
How might the papillary muscles be damaged?
Post MI
What can mitral incompetence cause?
Pulmonary hypertension
Right ventricular hypertrophy
What clinical CVS conditions can mitral stenosis lead to?
AF
Right heart failure
Pulmonary hypertension (due to back pressure)
Left atrial and right ventricular hypertrophy
When does mitral stenosis commonly occur?
Post-rheumatic fever
What is an problem concerning the heart blood flow that arises due to mitral stenosis?
Restriction of blood flow to left ventricle
What type of murmur is associated with mitral stenosis?
Opening snap and diastolic murmur
What type of murmur is associated with mitral incompetence?
Mid-systolic click and late systolic murmur in mitral prolapse
What type of murmur is associated with aortic stenosis?
Ejection systolic murmur
What type of murmur is associated with aortic incompetence?
Diastolic murmur
What is infective endocarditis?
The infection of a valve with formation of thrombotic vegetations
What determines the damage caused and the severity of the infective endocarditis?
Virulence of organisms
What is bacteraemia?
The presence of bacteria in the blood
Why are antibiotics used in a dental examination if the patient has had rheumatic fever in the past?
Since rheumatic fever is a predisposing factor to valvular disease, antibiotics are used to prevent bacteraemia and hence potential set up of bacteria in the valvular vegetations that may be present in resultant infective endocarditis
What are the three major risk factors associated with infective endocarditis?
Valve damage
Bacteraemia (dental & catheterisation)
Immunosuppression
What is rheumatic fever?
Acute multi-system disease - heart, (pericarditis, myocarditis & valvulitis) joints & connective tissue
What type of infection normally precedes rheumatic fever?
Streptococcal (usually pharyngitis)
What age group does rheumatic fever affect?
Children - 4-16 years old
What is the composition of a vegetation?
Group D streptococcus Gut commensals (bacteria) Skin strep (coxiella, fungi, candida)
What are the two main parts of infective endocarditis that must be carried out?
Blood culture
Intravenous antibiotics
What factors are part of the infective endocarditis diagnosis, treatment and prevention plan?
Treat strep infection with antibiotics Prophylactic cover for invasive procedures (e.g. dental work) Replace damaged valves Imaging BLOOD CULTURE INTRAVENOUS ANTIBIOTICS
