18. TEE for Congenital Heart Disease in the Adult Flashcards
Most common congenital heart lesion at birth?
VSD
Embryology of the Heart
4 Parts of heart as embryo:
- Bulbus cordis
- Primitive Ventricle
- Atrium
- Sinus venosus
- Initially a straight tube, undergoes looping such that convex surface of the heart on the right side (D-loop)
Development of Sinus Venosus
- become venous system of heart
- originally right and left horns connected by transverse sinus
- right horn enlarges and fuses with RA to become IVC and SVC
- left horn becomes atretic and becomes coronary sinus
- failure to do this produces persistent left SVC
Development of Atrium and Interatrial Septum
- Initially single atrium connected to ventricle
- Septation occurs when septum primum develops and grows inferiorly
- Septum primum leaves an opening, the ostium primum below its free edge
- Later, septum primum develops a second opening near the upper part of the septum called the ostium secundum
- Septum primum closes ostium primum
- Septum secundum forms to the right of septum primum, but leaves a hole near bottom called foramen ovale
Incidence of PFO in adults
20%
Separation of Atria and Ventricles
- Occurs following creation of septum primum
- Apposing masses of tissue, endocardial cushions, enlarge and fuse together
Development of Ventricles
- Combination of muscular intraventricular septum and outgrowths of endocardial tissue from conus and truncal swellings
- Produces septum with small membranous and large muscular portions
- Septum divided into inlet, trabecular and outlet regions
Development of Outflow Tracts
- Aorticopulmonary septum develops within single truncus arteriosus
- Twisting and ridge fusion required to produce aorta and PA
ASD Types
Four Types:
1) Ostium secundum (70%)
- defect in central intraatrial septum
- assoc with MVP and MR
2) Ostium primum (20%)
- inferior intraatrial septum
- assoc with cleft mitral valve and MR
3) Sinus venosus (10%)
- adjacent to SVC or IVC
- assoc with partial anomalous pulmonary
venous return
4) Coronary sinus (rare)
- communication between left atrium and
coronary sinus
- assoc with persistent left SVC
VSD Types
Four Types:
1) Perimembranous (70%)
- involves membranous septum
- assoc with ventricular septal aneurism
(composed of tricuspid valve tissue)
- assoc with AV cusp herniation and AI
2) Muscular (20%)
- muscular portion of septum
3) Doubly committed outlet (subarterial) (5%)
- aka supracristal
- immediately below pulmonary valve
- assoc with AV cusp herniation and AI
4) Inlet (5%)
- posterior portion of septum near AV valves
- combined with primum ASD =
atrioventricular canal defect
* common in Downs syndrome
Eisenmenger’s Syndrome
Long-standing VSD and pulmonary overcirculation resulting in pulmonary hypertension with reversal in the direction of blood flow through the VSD causing cyanosis
PDA (Patent Ductus Arteriosus)
- In fetal life, PDA connects junction of main and left PA to aorta, adjacent to left subclavian
- typically closes to become ligamentum arteriosus
- left to right shunt leads to pulmonary over circulation and pulmonary hypertension
- surgical closure contraindicated in those who already have developed Eisenmenger’s syndrome
Coarctation of the Aorta
- narrowing of the aorta beyond the origin of the left subclavian or insertion of ligamentum arteriosum (reminent of ductus arteriosus)
- assoc with PDA, VSD, bicuspid AV
- more common in males
- produces hypertension proximal to lesion and hypotension distal to lesion
- complications: aortic dissection, rupture, cerebral hemorrhage and LV failure
Aortic Stenosis
- Biscuspid AV most common malformation
- commisural fusion
- assoc with VSD, coartaction of aorta and
aortic aneurism
Pulmonary Stenosis
- Domed PV without clear leaflet separation is
most common malformation - Assoc with RV hypertrophy and obstructive subpulmonic hypertrophy and main PA dilation
- Also assoc with ASD and VSD
Peak gradient
80mmHg - severe, decrease life span to 30
yrs
Tetrology of Fallot
- Consists of VSD, RVOT obstruction, overarching aorta, RV hypertrophy
- VSD typically between right and non-
coronary AV cusps
- VSD typically between right and non-
- Assoc with absent PV, coronary anomalies, LVOT obstruction, aortopulmonary window
- Surgery includes closure of VSD and relief of RVOT obstruction
D- Transposition of Great Arteries
- Concordance of atrioventricular connection
and discordance of ventriculoarterial
connection - Morphologic LA drains to morphologic LV
then empties into PA - Assoc with ASD, VSD, PDA
- Cyanotic lesion since systemic and
pulmonary circulations are in parallel- ASD, VSD or PDA required for survival
Surgical correction
- Now = arterial switch and coronary
translocation
- Older procedure is atrial baffle (mustard or
senning)
* Systemic venous circulation re-routed
through mitral into LV and into PA
* Pulmonary venous blood re-routed through
tricuspid to RV to aorta
* RV is maintained as systemic pump
Congenitally Corrected Transposition (Levo-transposition)
- Discordance between atrioventricular connection and ventriculoarterial connection
- Morphologic RV on left, and morphologic LV on right
- AV valve follows ventricle
- SVC - RA - LV - PA & PV-LA-RV-Ao
- Systemic ventricle is RV
- Assoc with pulmonary outflow obstruction, VSD, tricuspid valve defects
- High incidence of AV block present –> need pacemaker
Single Ventricle Types
- Most involve hypoplasia of either RV or LV
- Common feature is mixing of systemic and pulmonary blood completely
Types
1) Double inlet LV
* Ventricles reversed and both atria open to
LV
2) Tricuspid atresia
* Blood travels from RA through PFO to LA to
LV to aorta through PDA to lungs
3) Hypoplastic left heart
* Reverse of tricupsid atresia with blood
traveling from LA through PFO to RA to RV to
PA through PDA to aorta
Single Ventricle Procedures
Procedures:
1) Norwood (Hyoplastic Left Heart)
* Neoaorta created to take blood from RV to
systemic. Original PA disconnected from
RV. Shunt from RV to PA placed to provide
some pulmonary flow.
2) Modified Blalock-Taussig shunt
* After Norwood, instead of RV to PA shunt,
shunt placed from aorta (or right subclavian)
to PA
3) PA Band
* Band across PA to limit overperfusion of
lungs. Ideally systolic PA less than 1/3
systemic
4) Glenn and Fontan (Tricuspid Atresia)
* Goal: Redirect venous through directly to
PA and bypass RV
* Bidirectional Glenn: SVC connected to PA
* Fontan: IVC to PA via baffle shunt
