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
Problem with vasodilators in AS
Contraindicated in severe AS
What surgical procedure is used to treat AS
TAVI (Transcatheter Aortic Valve implantation)
When should patients be given surgical symptomatic
- Decreasing EF
- Patients undergoing CABG
- Symptomatic patients (asymptomatic can be used for medical management)
Definition of Mitral Regurgitation
Back flow of blood from Lv to LA during systole
4 Causes of Mitral Regurgitation
- MVP
- Ischaemic MR
- Rheumatic heart disease
- Infective Endocarditis
Pathophysiology of Mitral Regurgitation
- Pure Volume Overload
- Compensatory mechanisms (LA enlargement, LVH and increased contractility
Pulmonary hypertension = left atrial dilatation continues and RVD
Progressive LV volume overload = dilatation and HF
Auscultation of Mitral Regurgitation
- soft S1 + pan systolic murmur at apex radiating to axilla
S3 (CHF/LA overload)
Displaced hyper dynamic apex beat
Exertion Dyspnoea
Heart Failure: May coincide with increased haemodynamic burden
Does intensity of murmur in Mitral regurgitation correlate with severity
Yes
How long does the compensatory phase in MR last for
10-15 years
How does mortality from MR occur
Progressive dyspnoea + HF
Investigations for MR
ECG
CXR
ECHO
ECG in MR diagnosis
LA enlargemet
Atrial Fibrillation
LV hypertrophy with severe MR
CXR in MR diagnosis
LA enlargement
Central pulmonary artery enlargement
ECHO in MR diagnosis
Estimation LA
LV size and function
Calve structure assessment
How is MR medicated
- Vasodilators (ACEI, hydrazine)
- Rate control for AF with beta blockers, CCB and digoxin
- Anticoagulation for AF
- Diuretics for fluid overload
Frequency of echocardiography in MR
Mild: 2-3 yrs
Moderate: 1-2 yrs
Severe: 6-12 mnths
When is surgical intervention for MR given
- Any symptomatic patients at rest
Asymptomatic patients ONLY;
- EF<60%, LVESD> 45mm
- If onset AF is new
What is aortic regurgitation
Leakage of blood into LV during diastole due to ineffective coaptation of the aortic cusps
What causes AR
- Bicuspid aortic valve
- Rheumatic
- I. endocarditis
Pathophysiology of AR
Combined pressure + volume overload
Compensatory mechanisms: Lv dilatation and LVH
Progressive dilatation = HF
Physical exam findings of AR
Wide pulse pressure: most sensitive
Hyper dynamic + displaced apical impulse
Auscultations
Auscultations for AR
- Diastolic blowing murmur at left sternal border
- Austin flint murmur at apex
- Systolic ejection murmur (due to increased blood flow across aortic valve)
How long does AR remain asymptomatic for
Until 4th or 5th decade
What are progressive symptoms of AR
Dyspnoea
Palpation’s (increased force of contraction and ectopics)
How does CXR help with AR
Cardiomegaly
Aortic root enlgarment
How does ECHO help with AR
Evaluation of AV and aortic root
Measurement of LV dimensions and function
How is AR managed
- Vasodilators (ACEIs in symptomatic or HTN)
- Serial echocardiograms
- Surgical Treatment
What patients should receive surgery for AR
EF drops below 50% or Lv becomes dilated
What is the S1 sound
The ‘LUB’ sound caused by mitral and tricuspid valve closure - AV valves
What causes the split S1 sound usually heard in a healthy adult
The mitral valve closes just before the tricuspid (more blood is usually flowing through the left side of the heart than the right)
What is the S2 sound
The ‘DUB’ sound caused by closure of the semi-lunar valves - pulmonary and aortic valve
What causes the normal S2 split in a healthy adult
Aortic valve closes before the pulmonary valve as blood flow is faster through the aortic valve (needs to close sooner)
In what condition is an S1 split heard in
Right Bundle Branch Block or Ventricular Tachycardia
Why can an S1 split be heard in RBBB
It is widened as more impulses are reaching the LV than the Rv so contracts more - delays closure of the tricuspid valve widening the split
What happens to the S1 split in LBBB
Less impulses to LV than to RV causing mitral valve to delay closure, overlapping with tricuspid valve closure - split is lost
When is an S2 split usually heard
During inspiration
Where is S2 split best heard
At left upper sternal border
Why is an S2 split usuallyheard during inspiration
Because there is increased venous return
Increased blood flow through the right side of the heart DELAYS closure of the pulmonary valve widening the split (aortic usually closes first anyways)
Aortic valve closes faster
In what condition sis a pathological S2 split heard in
Aortic stenosis
Hypertrophic cardiomyopathy
LBBB
Anything that delays closure of the aortic valve
What is a persistent WIDENED split
When A2 and P2 closure split can be heard throughout the process of respiration
What conditions cause a persistent WIDENED S2 split
ANY DISEASE delaying pulmonary valve and faster aortic valve closure
RBBBB
Pulmonary stenosis
Pulmonary hypertension
Mitral regurgitation
What condition is fixed split S2 an indication of
ASD
What is fixed split S2
Inspiration causes S2 split as normal
Due to atrial septal defect, we get reduced pressure in right atrium = More blood flow from LA to RA
More blood flow = delayed closure of pulmonary valve
What is the S3 sound known as
Ventricular gallop
When does ventricular gallop occur during the cardiac cycle
By the large volume of blood striking the LV as it moves in (passive ventricular filling)
When is S3 sound not normal
Over the age of 35
What condition is associated with S3 ventricular gallop
Systolic heart failure - myocardium is overly compliant resulting in dilated LV
Mitral regurgitation: Mitral leaflets stop blood flowing from LA to LV resulting in LA overflow and rapid LV filling (gallop heard loudly)
Ventricular septal defect: Rapid filling due to high pressure in RV to LV filling)
Dilated cardiomyopathy (overly compliant ventricles)
Where is S3 best heard
Apex of the heart
What position does the patient have to be in to best hear S3 sound
Left lateral decubitus position
S3 vs split S2 sound
S3 is low-pitched whilst S2 is high-pitched
What is the S4 sound
Atrial gallop
When does S4 sound occur in the cardiac cycle
JUST before S1 as atria contract blood into non-compliant ventricle (blood smashing against stiff ventricle)
What conditions result in S4 sounds
ANY condition that results in a non-compliant ventricle:
Diastolic heart failure
Aortic regurgitation
Why is S4 inaudible in AF
Because atria can’t contract properly (strongly enough) to force blood and make that smashing sound
Why is S4 heard in AS
Because the ventricle may hypertrophy over time causing a stiff ventricle to occur
S3 heard when ventricle initially dilates
