Mitral Regurgitation Flashcards
what is MR?
- backward flow from LV to LA during SYSTOLE through both isovolumic periods
Etiology of MR
- leaflet abnormalities
- chordae abnormalities (120 cords, can become thick, elongated, misdeveloped)
what is MV prolapse
- systolic bowing of belly of MV leaflets in systole to the LA
- > 2mm
percentage of people with MVP
2-5%
how many pap muscles are in the LV?
- 2
- posteromedial (1 CA)
- anterolateral (2 CA)
what happens to the pap muscles if the LV is dilated or hypertrophic
- misalignment may occur
what causes ischemic MR
- when an artery leading to the pap muscle becomes blocked, the wall is also affected, which causes dilation and abn tethering of chordae. Leads to MR
symptoms of significant MR
- dypnea
- palpitations
- arrhythmias
- CHF
- cardiomegaly
- murmur @ apex
- AFIB
what causes acute MR
- MI
- trauma
what happens to the LA in acute MR
- the MR fills a normal sized LA because it hasn’t had time to compensate by dilation
- pressure increases
- EF increases
- volume overload
what’s the role of echo in MR assessment?
- determine etiology of lesion
- assess LA size
- assess LV size % systolic function
- estimate severity of regurgitation
- estimate RVSP or other pulmonary pressures
which way does a jet flow in regards to a prolapse leaflet?
- jet always flows opposite side to prolapse leaflet
what happens on he M-mode trace with MVP?
- posterior displacement of the prolapsing leaflet in systole
what is tented MV?
- occurs when LV has dilated
- increased depth from MV tips to annulus
- pap muscles are being pulled away from the MV as the LV expands
what is more severe, small LA + large MR or large LA + large MR?
small LA + large MR (acute MR)
three indirect methods for grading MR
- colour MR jet area to LA area %
- Vena contracta
- PISA radius
what is entrainment
- blood sitting in LA getting displaced by incoming jet
- can overestimate MR severity
how to calculate MR area % of LA area
MR jet area% LA area
Vena contracta definition
- narrrowest part of jet downstream from narrowed orifice
- larger the convergence zone, more severe the regurgitation
what should the scale be shifted to when measuring pisa
30-40cm/s
how to measure the convergence zone for the pisa radius
- vertical distance from leaflets to top of convergence zone
T/F, the brighter the CW signal of MR, the more significant the leak.
true
what shape does severe MR look like
triangle
what happens to the pressure gradient between the LA and LV in severe MR
- the pressure lowers
total stroke volume definition
- the amount of blood that the LV pumps in a single beat.
forward stroke volume definition
- amount of blood that actually passes the AV and enters systemic circulation
regurgitant stroke volume definition
- amount of blood that backflows across abn valve
what do we need to assess MR with the pisa method?
PISA RADIUS
CW velocity @ radius
CW peak velocity @ MR jet
MR jet area mild & severe values
mild <4cm2
severe >8cm2
MR jet area to LA area mild and severe values
mild <20%
severe >40%
vena contracta mild and severe values
mild 0.7
PISA mild and severe values
<0.4
>0.9
regurgitant volume mild and severe
<30mL
>60mL
regurgitant fraction mild and severe values
<30%
>50%
