Embryology Flashcards
List 3 characterisitics of ASD no amenable to Amplatz device closure
ASD with partially anomalous venous drainage (ie., sinus venosus ASD)
Border of ASD with atrial rim < 4mm
ASD larger then 40 mm (largest device 40 mm)
Name collateral inflow in classic coarctation and outflow
Collateral inflow, proximal to obstruction from subclavian internal thoracic artery throcervival trunk vertebral Collateral outflow superior/inferior epigastric intercostal arteries
What is Cardiac septation?
Process that begins after looping morphogenesis has realigned the cardiac segments so that the right ventricular and left ventricular are located beside one another.
How does the atrial septum form
Atrial septum is made up of septum secundum, septum primum, and contributions from the atrioventricular cushions.
Septum secundum is an infolding in the roof of the common primitive atrium. Septum primum develops from the dorsal of the atrium and grows toward the atrioventricular cushions and closes off the ostium primum when it fuses with the atriovenitrcular cushions.
The septum primum develops fenestrations that coalesce into the ostium secundum
How does Ventricular septum form
Complex structure that involves components from the attrioventricular cushions, the muscular ventricular septum, and the conal septum. After looping the muscular septum is a ridge of myocardium corresponding to the furrow of the primary fold on the outer curvature of the heart. this separates the primitive left and right ventricle.
Muscular septum grows concordantly with the ventricles.
What are basic embroloy principles
Cardivascular system is first functional system in embryo
Blood circulation occurs by 3 weeks
Heart develops 3-8 weeks
Critical period for anomalies is 306 weeks
When is heart development
Endocardial tubes fuse to form heart tube (21 days)
Heart beings to beat (22 days)
Heart folding
D –right L (left) loop
Bulboventricular loop—future ventricles
Bulbus cordis—-conus cordis—RVOT
Truncus arteriosus—-great vessels
How does ASD occur
Ostium secundum—excess resorption of septum primum or inadequate development of septum secundum
Ostium primmum—septum primum fails to fuse with endocardial cusion
How does a VSD form
Malalignment
Muscular defect—resorption of septum
Failure of membranous portion to develop from extension of endocardial cushion to fuse with truncocoal septum
What are aortic arch clinical correlates
1, 2, 5, R6 all disapear
3—-carotids
4—mid arch
6–Right Pulmonary artery and ductus arteriosus
What is embrology of Tetralogy of Fallot
Unequal division of conus cordis
Name 3 fetal circulation shunts
Ductus Venosus—becomes the Ligamentum teres, venosum
Foramen Ovale—fossal ovalis
Ductus arteriosus—Ligamentum arteriosus
Shunts close after birth and become ligamentous
How is Foramen Ovale created
Derived from perforation that developed in septum primum as it fused with the endocardial cushions
What is secundum
Septum secundom is a RA ingrowth that is thicker and grows like a flap valve over septum primum in utero (non-obstructive
What type of congenital cardiac pathology causes cyanosis
Right to left shunt
How does a L to R shunt manifest in childhood
Failure to thrive
increased HR
increase RR
Hepatomegaly (1st sign in children)
List acyanotic congenital heart disease with increase pulmonary flow
VSD
PDA
ASD
List acynanotic congenital heart disease with normal pulmonary flow
Pulmonary stenosis
Mitral stenosis
Aortic stenosus
Coarctation of aorta
List cyanotic congenital heart disease with increased pulmonary flow
TGA (transposition of great vessels
TAPVR (total anomalous pulmonary venous return)
List cyanotic congenital heart disease with normal pulmonary flow
Pulmonary stenosis
Tetralogy of Fallot
ASD-Eisenmengers syndrom
What is Eisenmengers syndrome
Shift from a previous left to right shunt that now become a right to left shunt.
This represents a sign of increase pulmonary vascular resistance and pulmonary hypertension that maybe irresversible
What is a squatting action performed by an infant
a strategy to decrease the right to left shunting by increasing the systemic vascular resistance
When do most VSD close
6 months of age
When a VSD is going to cause a problem what is usually the age
usually 4 to 6 months of age
What are signs of heart failure in infants with large VSD
Tachypnea
Heptaomegaly
Poor feeding and failure to thrive
Management of VSD is dependent on what factors
size of defect
type of defect
shunt volume
PVR