8/14- Valvular Heart Disease 1 Flashcards Preview

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Flashcards in 8/14- Valvular Heart Disease 1 Deck (44):
1

What is stenosis?

Narrowing of valve that limits blood flow

2

What is insufficiency?

Leak across a valve that allows retrograde blood flow (aka regurgitation)

3

What are the determinants of blood flow through valves?

- Pressure difference

- Orifice geometry (valve area)

- Time of blood flow through the valve

Also:

- Fluid rheology

- Chamber stiffness

4

What is the pathophysiology behind valvular heart disease?

Valve injury causes overload

- Acute overload -> pulmonary edema

- Chronic pressure/volume overload -> hypertrophy

Hypertrophy-> Heart failure 

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5

Regurgitation causes what type of overload? Results in?

Regurgitation -> Volume overload -> Eccentric Hypertrophy

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6

Stenosis causes what type of overload? Results in?

Stenosis -> Pressure overload -> Concentric hypertrophy 

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7

What are some consequences of valvular heart disease (concentric or eccentric hypertrophy)?

Congestive Heart Failure

- SOB

- PND

- Orthopnea

- Rales

- JVD

- Edema

Arrythmias

- VT/Vfib (risk of sudden cardiac death, esp AS)

- A fib (with ALL, more with MS and MR) Infective endocarditis Embolism

8

What type of valvular heart disease most often causes VT/Vfib and sudden cardiac death?

Aortic stenosis

9

What type of valvular heart disease most often causes Afib?

Mitral stensosis and mitral regurgitation (although all can)

10

What underlies infective endocarditis? Consequences?

A structurally abnormal valve + turbulence is at risk for bacterial growth. May damage valves further with worsening regurgitation

11

For who is endocarditis prophylaxis routinely recommended?

- Prior Hx of endocarditis

- Prosthetic valves

- Cardiac transplant with valvular disease

- Congenital heart disease: cyanotic CHD or repaired with a prosthetic material in under 6 mo

12

What conditions make an embolism (systemic/cerebral) more likely?

Systemic and cerebral most likely with:

- Afib

- Large atria

- Large LV (e.g. DCM)

- Low EF

- Endocarditis (vegetations can break off)

13

Where are mitral valve murmurs best heard? Radiate?

Mitral valve

- Best heard at apex (about 5th ICS)

- Radiate to axilla

14

Where are aortic valve murmurs best heard? Radiate?

Aortic valve

- Best heard at base of heart over aortic area (2nd R ICS)

- Radiate to carotids/neck

15

In what state of the valve due stenotic and insufficient valves cause problems?

Stenosis: with normal flow across valve [systole]

Insufficiency: when valve is (supposed to be) closed [diastole]

16

List all the systolic murmurs

- Aortic stenosis

- Mitral insufficiency

- Tricuspid insufficiency (less common)

17

List all the diastolic murmurs

- Aortic insufficiency

- Mitral stenosis

- Tricuspid stenosis (less common)

18

Breakdown causes of aortic stenosis by age?

"Young" pts (under 70)

- Mostly bicuspid (earlier clinical onset, 50s)

- Rheumatic disease

- Degenerative*

Older pts (>70)

- Mostly degenerative

- BIcuspid

- Rheumatic disease

*Senile calcific "degenerative" later onset (70s-80s)

19

Average onset of bicuspid aortic valve stenosis/

Earlier (50s)

20

Average onset of senile calcific "degenerative" aortic valve stenosis?

Later (70s-80s)

21

What is shown here? 

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Bicuspid aortic stenosis

- Two cusps

22

What is shown here? 

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Senile calcific aortic stenosis

- Three cusps

23

Explain the mechanics of aortic stenosis causing murmur. What kind of heart failure

Obstruction to LV outflow

- Pressure gradient between LV and aorta

- LV pressure overload results in concentric LVH over time -> diastolic dysfunction (earlier) -> systolic dysfunction (later)

- Acceleration of systolic flow produces a systolic crescendo-decrescendo murmur at base radiation to neck

24

Explain the pressure gradient across the aortic valve in aortic stenosis?

- LVP > aortic P in systole

- Pressure in LV remains higher than aorta all through systole until it finally relaxes 

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25

What are some key physical exam findings of aortic stenosis?

Murmur:

- Systolic, crescendo-decrescendo

- At base (R and possibly L 2nd-3rd ICS), radiating into neck

- Coarse

Slow, weak carotid upstroke

PMI forceful, sustained

Soft S2 (if calcified, doesn't close quickly) with delayed A2 (takes longer for LV to empty)

- Single S2 or paradoxically split S2

26

What is the classical clinical triad of aortic stenosis?

Think of initials: A-S-D

- Angina/chest pain

- Syncope/SCD

- Dyspnea/CHF

27

What causes the angina/chest pain in aortic stenosis?

- Demand increases (LVH)

- Subendocardial flow decreases (high LV diastolic pressures)

- +/- coronary artery stenosis

28

What causes heart failure in aortic stenosis?

- Hypertrophy with fibrosis

- Chamber stiffness increases

- Diastolic failure first, later systolic failure

29

What causes syncope/sudden death in aortic stenosis?

Exercise-induced: fixed small orifice, so unable to increase CO

Unprovoked:

- Arrhythmia: Vtach or Vfib

- AV block 

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30

Describe the natural history of aortic stenosis (length of symptoms, survival...)

Long initial asymptomatic course

Once symptoms occur, prognosis worsens

Survival is:

- Worst with HF

- Better with syncope

- Best with angina (ASD triad)

31

Treatment for aortic stenosis? When done?

Valve replacement

- For severe, symptomatic aortic stenosis

32

What is acute aortic insufficiency?

Injury to aorta or leaflets -> sudden diastolic retrograde flow into LV resulting in heart failure

- No time for compensation

33

What is chronic aortic insufficiency?

The pathophysiology and leak evolve slowly over years

- Allows compensation by LV dilation

- Delays the onset of symptoms of heart failure

34

Causes of acute aortic insufficiency?

Aorta issues:

- Dissection!

- Trauma

Cusp issues:

- Infection

- Trauma

35

Causes of chronic aortic insufficiency?

Aorta issues:

- Marfan's (heritable)

- Inflammatory: syphilis

- Annulo-aortic ectasia

Cusp issues: (more common)

- Bicuspid valve

- Rheumatic disease

- Late sequelae of infection

- Prolapse

- Degenerative/senile

36

What are some key features (heart sound wise) of aortic regurgitation?

Diastolic regurgitation

- Causes LV volume overload

Diastolic murmur

- Due to regurgitation of blood into the LV

Murmur duration

- Shorter in acute than chronic b/c pressures "equalize" faster in acute AI

37

How to calculate % regurgitation?

regurgitation/totalSV

= regurgitation/(regurg + forward)

38

Describe LVP and AoP during aortic insufficiency

- Pressure difference between LVP and AoP during diastole is pretty significant; decreases with regurgitation back through aorta

- Quicker P equalization causes shorter murmur (earler diastole) (pic h)

39

What is the phathophysiology/consequences of acute aortic insufficiency?

Recall: acute AI = sudden disatolic leak

- LV enlarges, but only minimally (not enough time)

- Acute increase in volume in small chamber -> significant increases in LV diastolic ps

Acute pulmonary edema results

Effective forward CO is reduced acutely

-> low BP

-> circulatory collapse (shock)

40

What is pathophysiology/consequences of chronic aortic insufficiency?

Recall: chronic AI = progressive leak over years

- LV eccentric hypertrophy (LV dilation): compensatory increase in SV

- Diastolic BP drops due to AI, systolic P may rise (increased SV), causing a WIDE pulse pressure (SBP-DBP)

- Systolic function declines over years (less forward, more regurgitant volume)

- Further LV dilation and untimely CHF results

41

Key clinical findings of acute vs. chronic AI?

- BP

- CHF

- PMI

- Murmur

- EKG

- Echo

BP

- Acute: normal or low

- Chronic: wide pulse pressure, bounding pulse (large volume)

CHF?

- Acute: Severe CHF signs

- Chronic: No CHF signs

PMI:

- Acute: normal position

- Chronic: displaced, enlarged

Murmur:

- Acute: short early diastolic murmur

- Chronic: long diastolic murmur

EKG:

- Acute: no LVH

- Chronic: LVH

Echo:

- Acute: No LVH; Al jet

- Chronic: Eccentric LVH, Al jet

42

Treatment for aortic regurgitation?

- MIld/moderate: vasodilators (to decrease afterload, unload ventricle, and increase SV)

- Severe: valve and/or aortic root repair or replacement

- Acute: surgical emergency

43

Key Points of AI

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44

Key points of AS

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