Valve Disease Flashcards
What is valve stenosis
The narrowing of valves
What is valve incompetence
Valves becoming unable to shut properly
Which valves are under more pressure
Mitral and aortic valve
What are papillary muscles
Attach the valves to the heart wall and hold the valves shut during systole or diastole
Which valve doesn’t have papillary muscles and why
Aortic valve
It stays shut due to the high pressure in the aorta and only opens when the pressure in the left ventricle exceeds this
In which groups of patients is valve disease more common
Elderly patients
Patients with Down’s Syndrome
What are the symptoms of valve disease
Rarely any symptoms and often goes undiagnosed
What causes valve disease
Congenital abnormalities
MI - papillary muscle rupture
Rheumatic fever
Dilation of the aortic root
What is rheumatic fever
An immune reaction to streptococci that can lead to vegetations growing on the heart valve which can become infected and cause infective endocarditis
What is dilation of the aortic root
Makes the width of aortic root increase and pulls the aortic cusps apart so they no longer meet and don’t close properly
What can cause dilation of the aortic root
Aneurysm formation within the aorta
Syphilis
Give an example of a congenital abnormality that can cause valve disease
Bicuspid aortic valve instead of normal tricuspid appearance
What valves are found in the heart
Left - aortic and mitral
Right - pulmonary and tricuspid
Which valves fail more commonly
Left side valves - aortic and mitral
What is the outcome of valve stenosis
Limits blood flow into the ventricle reducing the ability of the heart to maintain an adequate cardiac output and cause heart failure
What investigations can be carried out in a patient for valve disease
Ultrasound scan
Doppler ultrasound scan
Describe a Doppler ultrasound scan for valve failure
Doppler measures whether the blood is moving away from the probe or towards it, the computer will then colour the blood artificially to demonstrate it flowing away and towards the probe
It can be seen whether the blood can flow past the valve cusps and back into a chamber or whether the blood isn’t properly being forced into a new chamber
When should valve replacement be carried out in a patient
Before evidence of heart failure as any heart failure that develops before the valve is replaced will not completely reverse after the treatment and also increases risk during the surgery
What are the different types of replacement heart valve
Mechanical
Biological
Describe a mechanical heart valve
Metal, long working - 20-30 years
Metal requires patient to take an anticoagulant to prevent blood clots from depositing on the surface of the valves and causing emboli and problems with stroke
Describe a biological replacement heart valve
Heart of pig, coupled onto a frame which can be implanted onto the cardiac tissue
Shorter life - less than 10 years
When is it best to use a biological heart valve
When known that the valve will need to be replaced in the future anyway
When the patients life expectancy is less than the life expectancy of the valve
What major risk does heart valve replacement have
Infective endocarditis risk
Which anticoagulant is currently used in patients with a metal valve
Warfarin
What may some patients not like about metal valves
Makes a ticking noise
How can the ticking noise of a metal valve help dentists
Allows dentist to recognise changes in the patients heart rate if they are becoming anxious during care
When should antibiotic prophylaxis be considered
During any heart valve replacement
How is a valve replacement carried out
Sutures placed through valve ring and heart tissue then valve is slid down the sutures and secured into place
What can a dentist do to prevent endocarditis
Remove cases or oral sepsis
Improve patients oral hygiene
Improve prevention of oral disease
