week 4 MR Flashcards
(43 cards)
MR etiology
primary cause vs secondary (functional) cause
primary cause - smt wrong with MV apparatus
secondary cause - dilated LV so MV doesn’t close properly (normal MV but smt wrong with heart)
What are some primary causes of MR?
MVP
flail leaflet
trauma
endocarditis
prosthetic valve malfunction
cleft MV
MAC (mild MR)
rheumatic fever (usually causes MS, sometimes causes MR)
What are some secondary causes of MR?
tethered leaflet
LV dilation
Ischemic causes
ruptured pap muscle
SAM
MV prolapse
MVP = bowing of >2 mm above the MV annulus
Myxomatous degeneration of MV
another name for MVP
called myxomatous degeneration of MV bc weakening of CT
Barlow syndrome
another name from MVP
Named after doctor who first described MVP
usually refers to most severe form of MVP
What causes MVP?
Don’t know!
Idiopathic
genetic
associated with CT disorders
MVP murmur
mid systolic click then late systolic murmor
click bc sudden tensing of leaflet as it is pushed into LA
If there is MVP of AMVL, what does the MR jet look like?
Eccentric jet, posteriorly directed
What does the m-mode look like if have MVP?
late systolic dip
use M-mode to determine timing of MVP: mid - late systolic dip? holosystolic?
Flail MV leaflet
caused by torn chordae tendineae = acute MR
MR: how to tell the difference btw MVP and flail leaflet in 2D
MVP - tip of the leaflet point towards LV
Flail - tip of the leaflet points towards LA
If there is a flail AMVL, what does the MR jet look like?
Eccentric jet, posteriorly directed
Can trauma cause MR?
yes, if MVA, look at
Right heart bc most anterior
MV - sudden severe MR bc ruptured chordae or pap?
Endocarditis
bacterial infection of heart valves - get vegetation or bacteria eats a hole in valve
More likely to cause MR than MS
Prosthetic valve malfunction
most prosthetic valves have trivial MR = washes out valve so no clots
Shouldn’t see significant MR
especially bad if leaking through sewing ring!
cleft MV
hole in leaflet, usually AMVL
rare, congenital
Tethered leaflet
post MI, the LV changes shape and pap muscle shifts more apically
= tightens chordae
= MV can’t close properly
LV dilation
post MI, LV dilates
= MV leaflets too far apart to close properly
Ischemic causes
We used to think that damaged paps bc MI caused MR…
new research shows that revascularization of paps does not improve MR
ruptured pap muscle
causes sudden severe MR - pap muscle is attached to leaflet with chordae and swings between LA and LV
bc trauma (MVA) or post MI (rare)
SAM
Systolic Anterior Motion of MV
Associated with hypertrophic cardiomyopathy (= thick IVS)
= narrowed LVOT sucks AMVL over
- more suctioning effect in late systole = more MR
Which MV pap muscle is more likely to rupture?
PM pap muscle bc its supplied by only one coronary
PM pap - PDA
AL pap - LAD and Cx
If there is SAM, what does MR jet look like?
eccentric MR jet, posteriorly directed