Valvular Heart Disease

Question 1

congenital aortic stenosis

Answer 1

• Bicuspid – MC
  
  • Person born with two leaflets instead of three
  • Theres a strong correlation between bicuspid valve and marfan system which affects the medial layer of the aorta and dissection of the thoracic aorta
    
    • Aortic dissection = MCC death in bicuspid
• Membranous subvalvar – can be very tricky to determine where problem is – occurs a lot in kids
• Fused leaflets with doming – they are flexible but because of the fusion, they dome upward due to the left ventricular systole

Question 2

Acquired aortic stenosis

Answer 2

• Acquired – much more common than congenital
  
  • Calcific – leaflets become sclerotic (we don’t know why)
    
    • You can see in renal disease where they have a lot of calcium phosphate
  • Hypertrophic subaortic – this is not actually stenosis of valve, but rather beneath it
  • Rheumatic – rheumatic fever typically affects the mitral valve

Question 3

pathophysiology of aortic stenosis

Answer 3

• Increased systolic ventricular pressure – this is like a body builder working out – muscle hypertrophies
  
  • First thing that happens is NOT loss of strength
• Left ventricular hypertrophy
  
  • Diastolic dysfunction – ventricle doesn’t relax as much because its so hypertrophied
    
    • Only later does the ventricle poop out because its tired
• Systolic decompensation
• Low pulse pressure, hypotension – if the ejection is impeded, the systolic doesn’t rise as high and because the vessels in the periphery are so constricted, the diastolic doesn’t fall as much

Question 4

symptoms of aortic stenosis

Answer 4

• Angina (triad #1) – pain in chest from inadequate coronary blood flow
  
  • Theres no obstruction in coronary artery
  • There is more demand for oxygen from the hypertrophied ventricle
  • EXERTIONAL angina
• Congestive heart failure – constellation of signs and symptoms
  
  • Diastolic – most common presentation with aortic stenosis – the muscle is so hypertrophied that for the ventricle to fill, the left atrial pressure rises and backs up into the lungs
  • Systolic
• Presyncope and syncope (Stokes-Adams attacks) – refers to presyncope and syncope caused by hypotension when the left ventricle cant maintain systolic pressure
  
  • Peripheral vasculature for muscles being utilized are still dilated, but as person slows down, there is a dip in blood pressure or loss in consciousness

Question 5

signs of aortic stenosis

Answer 5

• Systolic murmur
  
  • Thrill – palpable murmur, theres nothing different between murmur and thrill except that one is heard and one is felt
    
    • If you feel a thrill, because aorta is anterior, you can be pretty sure it is aortic stenosis
• Soft second heart sound
• Delayed arterial upstroke – normally the ventricle has ejected most of the blood, but now it takes longer to get all the blood out
  
  • If you can feel artery filling under your fingertips, that could be an indication of a delayed upstroke
• Narrow pulse pressure
• Rales and other signs of CHF

Question 6

diagnosis of aortic stenosis

Answer 6

• Symptoms
• Examination
• Echocardiogram
  
  • Increased leaflet thickness and echodensity with decreased excursion on structural views
  • Increased systolic velocity of blood flow (gradient) with reduced valve area on Doppler

Question 7

Echo findings in aortic valve area with aortic stenosis

Answer 7

• If you think about cars in a racetrack (oval), the rate of cars crossing past any point in that oval has to be the same or cars would be piling up
• Continuity principle: flow rate is constant regardless of where it is measured
• Flow rate in an orifice is equal to area multiplied by velocity
  
  • A(cm x cm) x V (cm/sec) = CO (cm­3/sec)
  • Outflow tract flow = Aortic valve flow
  • Aortic area X vel. = Outflow area X vel.
  • Aortic area = (Outflow area X vel.)/aortic vel.

Question 8

use of cardiac cath in aortic stenosis

Answer 8

• Aortic stenosis and coronary atherosclerosis often go hand in hand
• Systolic gradient across valve
• With cardiac output, valve area is calculated
• Echocardiogram superior to cardiac cath for above
• Cardiac cath primarily to evaluate coronaries: CAD frequently accompanies AS

Question 9

Aortic stenosis tx

Answer 9

• CHF from diastolic dysfunction may be treated with medication: diuretics
  
  • ONLY diastolic numbers are off – for any of the other classical triad, you have a mechanical problem with imminent trouble
• For any of the classical triad of angina, CHF (from systolic dysfunction), or Stokes-Adams attacks, mechanical intervention:
  
  • Valve replacement – THE SOLUTION
  • Balloon valvuloplasty – makes the valve a little more flexible – if you can increase valve area by 50%, results in a huge difference! But, this is not a permanent cure
    
    • Mostly for people who need urgent surgery but have aortic stenosis

Question 10

aortic stenosis valvuloplasty

Answer 10

• Only for calcific or rheumatic AS of trileaflet valves
• Respite is temporary, therefore use limited:
  
  • Palliation of nonsurgical candidates
  • Stabilization of patients requiring urgent major noncardiac surgery
  • Possible reduction of operative M&M during AVR in patients with poor LV contractility (theoretical)

Question 11

aortic stenosis valve replacement

Answer 11

• Mechanical: Indefinite durability at the price of chronic anticoagulation
• Heterograft: anticoagulation not necessary (in the absence of AF); durability finite
  
  • From another species – from a pig or constructed using pig endocardium
• Homograft: at one time more durable; rarely used now
• TAVR: Percutaneous delivery of a heterograft valve mounted on a balloon, supported by a stent
  
  • Transcutaneous aortic valve replacement
  • Tissue valve is sewn into metallic stent – stent is crimped onto a catheter with balloon on the end – inserted into femoral artery and up to the heart, balloon is expanded, valve is in place

Question 12

Aortic regurgitation: etiology (chronic)

Answer 12

• Hypertension (& other root dilatation) – the leaflets no longer coapt during diastole
• Arteriosclerosis
• Aortic stenosis – leaflets are so stiff that they often don’t come together well – results in some regurgitation
• Prosthesis: leaflet vs. perivalvular
  
  • Leaflet – in a mechanical valve, soft tissue can start to grow into the valve region
  • Endocarditis can eat through a leaflet or a tear in the leaflet
  • Perivalvular – if there is difficulty in surgery, there might be leakage around where the valve was sewn in
• Endocarditis
• Connective tissue diseases, e. g. Marfan’s
• Inflammatory diseases, e. g. RA, SLE
• Congenital disease
  
  • Bicuspid – can become frozen in open position
  • VSD – sometimes the jet from the septal defect can affect the aortic valve and cause leaflet malformation
  • Sinus of Valsalva aneurysm – the three pouches that are created by the shape of the aortic valve – sometimes they dilate and rupture – most common on right side of the heart
• Aortitis – can cause dilation and regurgitation
• Rheumatic – can stiffen the leaflets into a position where they can’t coapt
• Syphilis

Question 13

aortic regurgitation etiology (acute)

Answer 13

• Aortic Dissection
• Endocarditis
• Trauma
• Valve prosthesis
• Rupture of sinus of Valsalva aneurysm
• Rheumatic fever

Question 14

Aortic regurgitation pathophysiology

Answer 14

• Blood regurgitates into LV in diastole
• LV maintains net stroke volume by dilating – the stroke volume can double and that is how CO is maintained
• Acute decompensation: pulmonary congestion – the decrease in LV volume has not occurred
  
  • Diastolic pressure rises so high from the leakage, suddenly someone is in CHF (pulmonary edema)
• Chronic decompensation: LV systolic failure – has maintained normal stroke volume but when it tires out and ejection fraction falls, the decompensation occurs

Question 15

Aortic regurgitation sxs

Answer 15

• CHF
• Palpitation
  
  • Increased stroke volume
  • Arrhythmia

Question 16

aortic regurgitation signs

Answer 16

• Large stroke volume
  
  • Rapid upstroke
  • Wide pulse pressure
  • Displaced PMI with LV lift
• Low diastolic pressure
• High pitched early diastolic decrescendo murmur radiating to LSB and apex
• Systolic flow murmur, usually louder than diastolic – not because the valve is obstructing flow, but because of the volume of flow through the dilated aortic root which was not meant to handle such a large volume
• CHF

Question 17

Acute, severe aortic regurgitation

Answer 17

• Severe decompensation: Often pulm. edema because LV cannot handle the load
• Normal heart size – most people with HF have enlargement of at least one chamber of the heart
• Murmur may be inaudible: low output, wide open valve, noisy respiration
• LV diastolic pressure very high
  
  • Diastolic BP not low – because the two places that will allow it to drop cant allow this
  • S1 absent: mitral valve is closed
• The one clue = even if diastolic murmur is hard to hear, you should be able to heart the first heart sound because the ventricle is contracting hard – S1 here is missing!

Question 18

diagnosis of aortic regurgitation

Answer 18

• Symptoms and signs
• CXR: cardiomegally, CHF
• Echo-Doppler
  
  • Regurgitation by Doppler
  • Structural abnormalities, e. g. vegetation, dilated root, etc.
  • LV size and function
• Transesophageal: vegetation, abscess, aortic dissection
• Cardiac catheterization
  
  • Not needed for diagnosis
  • Can help estimate severity by aortography – echocardiogram has taken over
  • Assesses hemodynamic compromise
    
    • LVEDP
    • Cardiac output
    • Pulmonary pressures – when LV pressure rises, LA pressure rises, pulmonary pressure rises
  • Defines other disease, e. g. coronary

Question 19

natural history of aortic regurgitation

Answer 19

• Long period of compensation without symptoms
• Gradual LV enlargement with normal systolic function
• Symptoms and/or LV dysfunction associated with rapid deterioration
• LV systolic dysfunction w/o symptoms rare

Question 20

treatment of aortic regurgitation

Answer 20

• Medical
  
  • Afterload reducton
  • CHF treatment
  • Antibiotic prophylaxis
• Surgical
  
  • Acute, severe AR is an emergency
  • Chronic AR
    
    • Symptoms
    • Systolic dysfunction
    • Progressive LV dilatation (e.g. end systolic diameter greater than 55mm) a relative indication
  • AVR with endocarditis is often successful

Question 21

Mitral regurgitation etiology

Answer 21

• Coronary disease: papillary m. malfunction
• LV dilatation, any cause
• Endocarditis
• Myxomatous degeneration/prolapse – MVP
• Rheumatic
• Other connective tissue, incl. inflam. dis.
• Congenital

Question 22

Acute mitral regurgitation

Answer 22

• Chordal rupture: myxomatous, endocarditis, trauma
• Papillary rupture: infarction, trauma
• Acute papillary ischemia (usually circumflex)
• Valve perforation: endocarditis

Question 23

pathophysiology of mitral regurgitation

Answer 23

• Blood regurgitates into left atrium in systole
• LV compensates by enlarging
• Acute decompensation: congestion – CHF because LA pressure suddenly rises and atrium gets bigger to accept all the extra blood
• Chronic decompensation: LV systolic failure

Question 24

symptoms of mitral regurgitation

Answer 24

• Left CHF
• Secondary right CHF – from chronic elevation of pressure
• Symptoms of primary disease, e.g.
  
  • Angina
  • Fever

Question 25

signs of mitral regurgitation

Answer 25

• Systolic murmur
  
  • Typically holosystolic – aortic stenosis is a crescendo decrescendo
  • Can be late systolic if starts in mid systole
    
    • Papillary dysfunction
    • Prolapse after a click
• Left ventricular enlargement (PMI), if chronic
• Typical CHF signs

Question 26

diagnosis of mitral regurgitation

Answer 26

• ECG
  
  • LAA – characteristic p wave change
  • LVH
  • Atrial fibrillation – atrium is being stretched and provoked with high pressure
• CXR
  
  • LA enlargement
  • LV enlargement
  • CHF
• Echocardiogram
  
  • Semi-quantitative MR estimation
    
    • Depth and width of jet
    • Volume of left atrium filled
  • Quantitative
    
    • Orifice area, analogous to aortic stenosis
  • Etiology
  • LV function & other consequences
• Cardiac catheterization
  
  • Etiology and/or other disease, e. g. CAD
  • Angiographic presence of MR and semi-quantitative severity confirmed, but echo better
  • Large “V” wave in pulmonary wedge pressure – put a catheter into a vein and thread it down the pulmonary artery until its jammed – you are then looking then at a reading in left atrium
  • LV size and contractility confirmed, equivalent to echo
  • Hemodynamic effects: output & RH pressures

Question 27

treatment of mitral regurgitation

Answer 27

• Medical: Analogous to AR
  
  • Treat the underlying disease
  • Endocarditis prophylaxis
  • Afterload reduction
  • Other treatment for CHF prn
  • Arrhythmias prn
• Surgical
  
  • Timing was the hardest issue, now easier
    
    • Certainly when symptomatic despite medication
    • Before LV deteriorates: post-op afterload is higher
  • Valve repair is increasingly common
    
    • Shorten or reattach chords
    • Tuck leaflets
    • Reduce annular diameter with a ring
  • Its important to do surgery before the ejection fraction becomes abnormal – if you correct after the ejection fraction is affected, then you will actually make it worse
• Catheter based
  
  • Repair with clips and/or annular rings
    
    • MitraClip is approved
  • Replace the valve
• Numerous valves that can be delivered on a catheter are under development

Question 28

Tricuspid regurgitation etiology

Answer 28

• Right ventricular failure or dilatation
  
  • Pulmonary hypertension
    
    • Primary: rare
    • Secondary: LV failure, mitral disease, lung disease, Eisenmenger syndrome (end stage volume overload, e. g. atrial or ventricular septal defect)
• Endocarditis, especially IV drug users
• Rheumatic: very rare as primary lesion

Question 29

Tricuspid regurgitation signs and symptoms

Answer 29

• If its pure right sided tricuspid regurg not secondary to anything, then you have true right sided HF
• Right sided CHF
  
  • Edema
  • Ascites
  • Reduced exercise tolerance
• Large “V” waves in the jugular veins
• Usually a murmur is not audible
• Primary disease, e. g. COPD or endocarditis

Question 30

Tricuspid regurgitation treatment

Answer 30

• Medical
  
  • Underlying condition
  • Diuretics – use for CHF
  • When these fail, surgical approach is necessary
• Surgical
  
  • Must treat the primary lesion (e. g. mitral)
    
    • Sometimes that is enough
  • Tricuspid annuloplasty with ring
  • Valve replacement is uncommon