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
