Mitral Regurgitation Flashcards
(34 cards)
What is Mitral Regurgitation (MR)?
Retrograde flow into the LA through the closed MV during systole, while valve is supposed to be closed
MR Clues often seen where?
2D echo & Color Flow
What is the MR murmur?
Holosystolic murmur that radiates to the axilla, high pitched blowing
What are causes of MR?
Rheumatic Fever, Annulus dilation, MAC, MVP, MS, Flail Leaflets, Vegetations, Chordae rupture, pap rupture, Congenital, LVE
What are complications of MR?
Volume overload in LA, leading to LAE and increased LAP, LVVO pattern due to increased preload(volume in the LV during end diastole) which leads to LV dilation, leading to LV hypertrophy, long standing MR leads to PHTN
Symptoms of MR?
Often none, Fatigue, DOE papitations, CP, CHF
What happens with MR?
Normally SV is 70-100cc ejected each beat, but with MR, SV increased LV + MR in LA»_space; LV volume overload (LVVO) over time
What is Preload?
Amount of diastolic filling of the ventricles
How does increased preload affect conditions of the heart?
Increases cardiac performance to a point, Frank-Starling Law
How does increased preload affect physiologic response of the heart?
Hyperdynamic, Contracts stronger, stronger squeeze at that moment
Preload & MR
LVVO pattern, Chamber dilation (LA-LV) & hypercontractility to maintain CO
Frank - Starling Law? or Length - Tension
The greater the stretch of the cardiac muscle cell(length or preload), the greater the force of the contraction(tension), to a limit, then contractility begins to fail
2D Echo signs for MR?
Defect of the MV that inhibits closure valve, LAE, LVVO, LVE, LV hypertrophy, RVE
M-Mode findings for MR?
hypercontractile motion , LVE, LVVO, AOV notching mid-systolic closure, LAE, PHTN,
Chronic MR leads to what?
LAE, LVE, increased LAP leads to PHTN, which leads to LV no longer compensating and muscle fails = decompensation
Acute MR result of?
MI or IHD/CAD, pap rupture or dysfunction, PHTN
MR color flow used for?
Semi-quantitative, time saver, shape and direction, increases accuracy of spectral doppler
Grades of MR?
- Grade I - Mild - 1+ - < 20% LA, jet extends just beyond MV leaflets
- Grade II - Moderate - 2+ - 20-40% LA, jet extends 1/3 into LA
- Grade III - Moderate - Severe - 3+ - > 40% LA, jet extends into 1/2 into LA
- Grade IV - Severe - 4+ - jet extends to back of LA, into pulm veins
RJA?
Regurgitant Jet Area: Trace MR in PLAX, PSAX, Ap 4, Mild 8cm squared
RJA/LAA?
Method of using trace of MR jet & trace of LAA to get ratio of jet to LA size, Mild < 20%, Severe > 40% (usually visually estimated)
What is the Vena Contracta?
Uses CF to estimate width(diameter) of
narrowest opening the regurgitant flow passes through, larger = more severe, mild < 0.3cm, severe > 0.7 cm, PLAX, Ap 4
What is PISA?
Proximal Isovelocity Surface Area - uses CF to identify flow convergence region, which is the golf ball area of flow for example in MR in the LV (proximal to MV)
MR CW Doppler evaluation?
Uniform signal strength, well defined signal, increased mitral flow velocity = more severe
What is MVP?
Mitral Valve Prolapse, Leaflet bowing back beyond plane of MV annulus by > 3mm
