Valvular Heart Disease Flashcards
What is the most common cause of mitral stenosis
Rheumatic heart disease
Rheumatic fever due to infection by group A beta-haemolytic streptococcus
What gender does mitral stenosis commonly effect
Women
In what part of the world is mitral stenosis common in
Developing world
Pathophysiology of mitral stenosis
- Orifice area reduced from 4-6 cm^2 to less than 1cm^2
- To keep CO constant, left atrial pressure increases = left atrial hypertrophy and dilatation
- Pulmonary venous, pulmonary atrial and right heart pressure increases as a result
- Increase in pulmonary capillary pressure = pulmonary oedema
- Pulmonary hypertension
Consequence of mitral stenosis causing pulmonary hypertension
- Right Ventricular hypertrophy
- RV dilatation
- Failure of tricuspid regurgitation
How long is mitral stenosis asymptomatic for
Until orifice is less than 2cm^2 small
Symptoms of mitral stenosis
- Severe dyspnoea (due to LA pressure increase, vascular congestion)
- Bloody coughs (rupture of bronchial vessels)
- Pulmonary hypertension = R HF
- LA hypertrophy = AF
- AF = systemic emboli
Clinical signs of mitral stenosis
- Bilateral cyanosis in cheeks
- Prominent ‘a’ wave in jugular vein pulsations due to pulmonary hypertension + RV hypertrophy
- Right heart failure will cause distension of jugular veins
What is mitral stenosis
Obstruction of LV inflow that prevents proper filling during diastole
How does Mitral stenosis cause mortality
Progressive pulmonary congestion = infection and thromboembolism
How are heart sounds effected in Mitral Stenosis
Low-pitched diastolic rumble at apex
Loud opening S1 snap
When is diastolic murmur in Mitral Stenosis best heart
Patient lying on the left side in held expiration
Does intensity of the diastolic murmur in MS correlate wit the severity of the stenosis
No
Where is the loud opening S1 snap best heart at
Apex
Why is there a loud opening S1 snap
Due to the abrupt halt in leaflet motion in early diastole, after rapid initial opening + fusion at leaflet tips
What heart sound indicates a more severe MS
Shorter S2 opening snap interval
Three diagnostics used to evaluate MS
ECG
CXR
ECHO
How would an ECG help with MS
Shows Atrial fibrillation + LA enlargement
How would CXR help with MS
LA enlargement + pulmonary congestion - calcified MV
How would Echocardiography be used to DIAGNOSE MS
Mitral valve mobility, gradient and mitral valve area
How is MS managed
Serial echocardiography:
Mild (3-5 yrs)
Moderate (1-2 yrs)
Severe (yearly)
Medication: Beta-blockers, digoxin will control HR and prolong diastole to improve ventricular filling
Diuretics for fluid overload
What people should be given mitral valve replacement
Symptomatic patient with NYHA Class III or IV
Severe MS
Pliable valve suitable
Normal size of an aortic valve
3-4 cm^2
When do symptoms occur in aortic stenosis
1/4th of normal size
Three types of aortic stenosis
- Supravalvular
- Subvalvular
- Valvular
Pathophysiology caused by aortic stenosis
- Pressure gradient develops between LV and aorta (increased after load)
- LV function maintained by compensatory LV hypertrophy
- LV function eventually declines
Presentation of aortic stenosis
- Syncope
- Angina (increased myocardial oxygen demand)
- Dyspnoea (on exertion due to HF)
- Sudden Death
Physical signs of aortic stenosis
- Slow rising carotid pulse + decreased pulse amplitude
- Heart sounds - soft or absent second heart sound + S4 gallop due to LVH
- Ejection systolic murmur (crescendo-decrescendo character)
Does loudness of sounds caused in aortic stenosis tell you anything about severity
No
Can onset of symptoms in aortic Stenosis be a good prognostic indicator
No
Prognosis of Angina + AS
5 years survival
Prognosis of Syncope + AS
Survive 3 years
HF + AS
Survival is <2 years
How is AS investigated
Echocardiography :
LV size + function (LVH, dilatation and EF)
Doppler-derived gradients + valve area
How is AS managed generally
- Dental hygiene/ care
2. Consider IE prophylaxis in dental procedures
Medical management of AS
Surgical replacement