Lai Echo AVSD

AVSD Echocardiography (Lai15)

=endocardial cushion defect xx--> both atria are connected to a common AV valve, usually w ASD and VSD and abNl valves

-endocardial cushions, made of mesenchyme --> sup, inf, R and L cushions

-sup and inf cushions contribute to atrial outlet and ventricular inlet

-Lai divides the lesions into complete and incomplete

-Complete AVC- primum ASD w communication at ant=inf margin of FO next to AV vlvs, && a large post VSD along the septal leaflet of AV vlv, extending into membr septum--> scopped out look to IVS

--> common AV annulus, usually w at least one mural or lateral leaflet exclusively over the right and one exclusively over the left, and remainder over both (2 bridge the crest of the IVS in sup/inf position)

-the sup leaflet distorts the AV jct to --> undwedge (superiorly displace) Ao outflow so Ao annulus is no longer bn the TV and MV, but is more anterior/superior --> longer LVOT (apex to Ao vlv) and shorter distance bn AV vlv and apex (usually they are = in Ln)

-the inf bridging leaflet cords attach to crest of IVS, while sup leaflet cords attach vary (and determine the Rastelli type...)

-Rastelli Classification for CAVC:

-A) sup leaflet divided at level of IVS

-assoc w pre-op LVOTO bc it--> longer LVOT

-B) sup leaflet divided to to a RV pap muscle (rarest)

-C) sup leaflet is undivided (free floating) (common w Down's)

-rarely w CAVC, the AV vlvs sit superiorly in the defect, so no primum ASD and only a big VSD

-Incomplete (Partial) AVC- comm'n at the canal part of AS (ant-inf margin of FO and AV vlvs) (a primum ASD), and 2 AV vlv orifices (but only 1 annulus).

-here the AV valve tissues adheres to the IVS--> forms a tongue connecting inf and sup leaflets--> no ventric level shunting

-so, there are 2 orifices, but the valves aren't Nl

-it is said that their is a "cleft" in the ant mitral valve leaflet, but this is a misnomer because a cleft is a deficit in the AV vlv tissue, but the sup/inf bridging leaflets meat at the IVS

-Transitional AVC- intermediate form on the spectrum- signif chordal attachment of sup bridging leaflet to the IVS w some shunting thru these cords at ventric level; the VSD is restrictive; PAP is <syst P

-the LV ant-lat pap muscle is often displaced posteriorly

-L AV vlv abNlies seen in 1/20 pts- usually double orifice or single pap muslce (parachute vlv) (more w incomplete than complete CAVC), and are assoc w unbalanced defects to RV with LV hypoplasia

--> xx for surgery, and --> regurg

-Assoc xx = TOF (esp Downs), PDA, CoAo, LVOTO; asplenic heterotaxy

-Note that an inlet-VSD (aka AVC type VSD) can occur w/o CAVC- defect along the septal leaflet of the TV, often w TV cord straddling into LV

Goals:

[ ] ASD size

[ ] VSD size

[ ] AV annulus, vlv, cord attachment anatomy

[ ] AV vlv relation to AV septum

[ ] Rastelli type

[ ] AV vlv leaflet assessment

[ ] AV vlv anomalies (e.g. Ebstein's)

[ ] LV pap muscle spacing

[ ] Balanced/Unbalanced atria and ventricles

[ ] relation of atrial septum to inlet

[ ] distribution of AV vlv over the ventricles (fr subcostal view)

[ ] AV vlv annulus and inflow into the ventricle by color in unbalanced CAVC (fr AP4C)

[ ] severity of ventricular hypoplasia

[ ] LVOTO and etiology if present

[ ] Hemodynamics

[ ] flow direction of ASD & VSD- color/Doppler

[ ] pk instantaneous P grad across the VSD to estimate RVP by CW

[ ] AV regurg severity by color

[ ] Assess RV hemodynamic load (dilation, incr Q thru pulm outflow and L AV vlv inflow)

[ ] RV syst P estimate by TR jet on CW (only can be done if restrictive/no VSD

[ ] LV or RV outflow tract obstruction/severity

[ ] Biventric fx

[ ] Assoc lesions- PDA, CoAo, 2nd ASD, other VSD, TOF

Imaging

COMPLETE CAVC

Subs:

-subs great for atrial septum and relation of AV vlv to the septum

-SCLA & LAO (in bn LA and SA) - sweep --> 1y ASD size & other ASDs

-color for shunting

-SCLA- see Ao unwedging and long LVOT (gooseneck deformity)

-SC LAO for AV vlv en face to check apportion to ea ventricle (check balance)

-SCSA- check AV vlv anatomy, cord attchmt to IVS (Rastelli class)

-SCSA- ddx bn Nl TV/MV and a common AV vlv

-subs often poor for VSD bc they don't highlight the edges

-SCSA good for pap muscles (often counterclockwise position relative to Nl heart);

-check for solitary pap (-->hard to fix MV valve)

AP4C:

-not good for ASD bc of false dropout bc ur parallel to it

-good for AV vlv orientation in the AVSD, so good to check VSD size

-check cord attachment relative to IVS

-check AV vlv inflow and AV regurg

-AP5C good for LVOTO and PW/CW

-PSLA- estimate severity of AV regurg

-Low L PSSA- image atrial septum

-PSSA at VSD- see VSDs/muscular VSDs

-Sup & Inf bridging leaflets of L AV vlv seen

-see "cleft" in the AV vlv

-see pap muscle orientation

INCOMPLETE/TRANSITIONAL CAVC

-as above

-SCLAO and SCSA good to see the 2 AV vlvs are abNl w bridging of sup leaflet across the IVS

-on SCSA see that the L AV vlv leaflet is perpendicular to where a Nl MV vlv ant leaflet is

-SCLAO shows 1y ASD well

-check for double orifice MV

-AP4C- see AV vlv position relative to IVS

-see AV vlv regurg, often via the cleft

-with a Transitional CAVC, the amt of ventric level shunting is minimal

-PSSA- align VSD jet for check of RV P

LVOT

-LVOTO common, espec in incomplete form and in Rastelli A

-bc abNl cord attchmts to L side of IVS, discrete subAo membrane, septal hypertrophy, anomalous/prominent anterolat pap muscle

-AP5C good for LVOT

-PSLA also good for LVOT

UNBALANCED CAVC

-SCLAO and SCSA good to check relation of AV vlv to ea ventricle

-AP4C good for severity of ventricular hypoplasia

-check color flow

-Markers of LV Adequacy for biventricular repair:

-direction of Q at VSD in systole (R-->L is a R/F)

-direction of Q at transverse Ao Arch (retrograde Q is a R/F)

-check for distal levels of obstruction- outflow, arch...