Mitral Regurgitation

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Mitral Regurgitation MVP

• S. Craft
• DSP 216

2
What is MR?

• Retrograde flow into the LA through the closed MV
  during systole
• 1. Seen on CFD
• 2. Clues often seen on 2D (MVP, MAC, MS, poor LV
  fx, chamber enlargement, etc.)

Can be chronic or acute MR
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Diagnosing MR

• 1st-make clinical diagnosis
• physical exam
• auscultation blowing, high pitch holosystolic
  murmur
• echo/Doppler
• Remember regurgitation a.k.a. insufficiency

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Symptoms

• Murmur
• High pitched, blowing holosystolic at apex
• Fatigue
• DOE
• Palpitations
• CP
• CHF (HF)
• Rt. HF

• CHF (Lt.HF)
• Dyspnea PND
• Cough
• Wt. gain
• Rt. HF
• JVD
• LE edema ascites
• hepatomegaly

5
What happens?

• Normally
• amount entering LV amount ejected from LV in
  systole
• Stroke volume (SV) the amount of blood (ccs)
  ejected by the LV with each beat
• 70-100cc normal range

• With MR
• in systole the LV ejects blood into the aorta but
  also some back into the LA
• Now, SV amount entering LV amount ejected
  into LA so the SV increases results in LV volume
  overload (LVVO) over time

both LA LV
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Preload

• The amount of diastolic filling of the heart
• can be measured by Doppler using end-diastolic
  pressure msmt or invasively by PCWP device
• How does MR affect preload conditions of the
  heart? Physiologic response of the heart?
• Effect chamber dilation (LA, LV)
  hypercontractility (to maintain CO)
• Reynolds Prep p. 156

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Effect of preload

• Frank-Starling law
• The greater the stretch of the cardiac muscle
  cell (length or preload), the greater the force
  of contraction (tension).
• To a limit, then contractility (sys fx) begins to
  fail

8
Cardiac output (CO)

• Amount or volume of blood ejected by LV per
  minute
• CO SV x HR
• normal range 4-8 l/m (liters per minute lpm
  L/m)

9
Chronic MR

• MR will eventually lead to LAE, LVE
• volume overload of lt. heart
• LA size has been increasing, to accommodate MR
  volume maintain fairly normal LAP
• As LAP increases,
• PAP increases leading to PHTN
• Finally, LV can no longer compensate muscle
  fails

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Cont.

• M-mode of LVE hypercontractile motion (LVVO
  pattern)
• over time, may cause increased LV mass

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Acute MR

• Usually result of MI or IHD/CAD
• PM rupture or dysfunction
• Sudden severe amount of MR is dumped into normal
  sized LA
• pressure overload of LA pulmonary vasculature
• sudden significant increase in LAP
• increased pulmonary pressures gtgtgt PHTN
• No chance to adjust/compensate

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MR etiologies-numerousRole of echo

• Identify presence
• Determine etiology
• MVP, MV disease
• ischemic heart disease (PM dsyfx)
• LVE
• ruptured chordae PM
• congenital defect
• underlying disease (CM), other

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PW Doppler in MR severity

• Estimate severity
• LA/LV size msmts
• PW Doppler mapping
• SV placement
• jet length (grading)
• jet area in the LA
• systolic flow reversal in pulmonary veins
  severe MR
• everything has pitfalls

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CW Doppler in MR

• CW Doppler evaluation
• signal strength
• uniform
• staining compared to fwd flow signal
• well-defined signal
• forward velocity
• increase in forward mitral flow is c/w more
  significant MR

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Spectral Doppler calcs

• Use 2D msmt spectral Doppler to calculate
• Regurgitant Volume (RV)
• Regurgitant Fraction (RF)
• Effective Regurgitant Orifice (ERO)
• Reynolds Pocket p 347-348
• more about these in DSP 231

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Color Flow Doppler in MR

• Semi-quantitative
• Time saver
• Increases accuracy of spectral Doppler aids in
  locating jet
• Used in RJA calc
• For shape direction
• eccentric, central, A/P directed jet, length

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Grading MR

• Grade I Mild 1 lt 20 LA
• jet extends just beyond MV leaflets
• Grade II Moderate 2 20-40 LA
• jet extends into 1/3 of LA
• Grade III Mod-Severe 3 gt 40 LA
• jet extends into 1/2 of LA
• Grade IV Severe 4
• jet extends to back of LA, into pulm. veins

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Mild Moderate Severe
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CF of mild moderate MR
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Regurgitant Jet Area calcs

• RJA Method of estimating MR by planimetry trace
  of CF jet of MR uses multiple planes
• has drawbacks
• RJA/LAA Method using trace of MR jet trace of
  LAA to get ratio of jet to LA size
• In practice most MR grading is done visually
  according to the grading system
• Reynolds Pocket p. 16-17, 342

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Vena Contracta

• Uses CF to determine the width (diameter) of the
  narrowest opening through which the regurgitant
  flow passes
• Refer to next slide to identify vena contracta
• Reynolds Pocket p. 343

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PISA for MR

• Uses CF to identify flow convergence region
• See any text
• RPkt p. 344
• Vena contracta Vs flow convergence area

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Putting the info together on MR

• Estimate MR severity
• LA size ?
• LV size ?
• LV hypercontractile?
• PHTN ?
• It should all go together to make sense
• Learn to use all calculations! None are perfect.

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Treatment of MR

• Serial echo exams to track progress symptoms
• LV size function response to meds
• Repair Vs replacement
• Treat underlying conditions
• Balloon valvotomy
• Carpentier ring - annulus support
• valve replacement

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Mitral Valve Prolapse(MVP)

• One or both leaflets bowing back into LA beyond
  plane of MV annulus by 3mm
• Myxomatous MV disease, Barlows syndrome, floppy
  valve, systolic click murmur

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Causes

• Exact cause is unknown usually is an abnormally
  large leaflet area sometimes due to abnormal
  collagen synthesis
• Myxomatous degeneration of MV leaflet
• Hereditary factors
• Isolated or associated with congenital
  disorders, skeletal abnormalities
• Functional MVP from other abnormality

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Symptoms Complications

• Murmur mid-late systolic click (w/wo MR murmur)
• Most people are asymptomatic
• May have fatigue, dyspnea, CP, palpitations,
  arrhythmias, dizziness, syncope
• Progressive MR associated sequelae
• Increased risk of bacterial endocarditis
• Ruptured chordae
• Embolic events
• HF
• Death is rare from MVP

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Treatment

• Serial echo exams to track progress symptoms
• Prophylactic antibiotics for any invasive
  procedure (dental, TEE, OR, etc)
• MV repair/replacement if warranted

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M-mode

• Mid-late or late systolic buckling of leaflets
  associated click on auscultation
• Holosystolic (pan-systolic) hammocking

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2D MVP
Myxomatous leaflets
Prolapse of both leaflets
Prolapse of PMVL
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Doppler

• MR is often associated
• Use PW CW
• Color Flow Doppler
• MVP of PMVL produces an anteriorly directed jet
  of MR
• MVP of AMVL causes posteriorly directed jet

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References

• Allen- DMS Echocardiography, 2nd edition
• Feigenbaum- Echocardiography,6th edition
• Otto- Clinical Echocardiography,3rd edition
• Reynolds- Pocket Reference, 2nd/3rd edition CV
  Registry Prep Guide