Congenital Heart And Other Defects Flashcards
Process of primitive heart tube formation
Cardiogenic mesoderm -> angiogenic cell clusters -> left and right endocardial tubes -> primitive heart tube
What is each endocardial tube continuous with
Dorsal aorta
Vitelloumbilical vein
What types of folding occurs in the primitive heart tubes
Cranial folding
Lateral folding
When does fusion of the 2 endocardial tubes to form the primitive heart tube finish
Day 21
What does the primitive myocardium form from
Mesoderm from foregut
When does the heart start to beat
Day 22
What causes the foramen ovale to close at birth
Left atrium pressure becomes higher than right atrium pressure
What does the heart septum form from
Septum primum
Septum secundum
How does the outflow tract of the heart partition
Neural crest forms bulbar ridges which grow and spiral
How many pairs of aortic arch arteries sprout from the aortic sac
5 (1-6 but 5 disappears)
What type of congenital heart defect is linked to migraines
Septal defects
Does a septal defect cause left right or right left shunting
Left right
How can septal defects be closed with
Fabric
Pericardium
Outflow tract defects
Persistent truncus arteriosus
Transposition of the great vessels
Tetralogy of fallot
Coarctation of aorta
Persistent truncus arteriosus
Pulmonary artery starts some distance above undivided truncus
What causes persistent truncus arteriosus
Truncoconal swellings fail to fuse
Transposition of the great vessels cause
Truncoconal septum straight instead of spiralled
Most common cyanotic heart defect
Transposition of great vessels
What causes tetralogy of fallot
Unequal separation of conus
4 characteristic features of tetralogy of fallot
Pulmonary trunk stenosis
ventricular septal defect
Overriding aorta
Right ventricular hypertrophy
VORP
2 types of coarctation of the aorta
Pre ductal - before ductus arteriosus
Post ductal - after ductus arteriosus
How can the ductus arteriosus be kept open in preductal coarctation of the aorta pts
Alprostadil - prostaglandin E1
Which type of coarctation of the aorta causes collateral circulation development
Post ductal
How can coarctation of the aorta be surgically treated
End to end flap anastomosis
Subclavian flap
Balloon angioplasty
Fetal circulation connections
Foramen ovale
Ductus arteriosus
Ductus venosus
Is resistance higher in the fetal pulmonary circulation or systemic circulation
Pulmonary
How long does the ductus arteriosus remain open after birth
24-48hrs
Fully within 1 wk
How long does the foramen ovale stay open after birth
Closes almost immediately
Persistent pulmonary hypertension of the newborn
Elevated pulmonary vascular resistance resulting in right to left shunting of blood and hypoxemia
Causes of persistent pulmonary hypertension of the newborn
Parenchymal lung disease
Lung hypoplasia
Idiopathic
Persistent pulmonary hypertension of the newborn treatment
Manage underlying cause
Mechanical ventilation
Inhaled NO
Prostaglandin - PGE1/PGI2
Sildenafil
Milrinone
Patient colour in cyanotic and Acyanotic defects
Cyanotic - blue
Acyanotic - pink
neural tube defects
Failure of normal closure of neural tube
Examples of neural tube defects
Spina bifilar occulta
Meningocoele
Myelomeningocoele - spina bifida
Encephalocoele
Anencephaly
Effects of Myelomeningocoele
Loss of bladder control - Incontinence/urinary retention
Fecal incontinence
Paralysis
Loss of sensation in legs
Meningocoele
Sac of CSF comes through opening in back
MyeloMeningocoele
Sac of CSF containing spinal cord and nerves comes through opening in back
Myelomeningocoele treatment
Closure - decr infection
Closure in utero - improve outcome
Hydrocephalus treatment
VP shunt
Gastrischisis
Full thickness defect in abdominal wall lateral to umbilicus allowing bowel to extend outside body
Gastroschisis treatment
Reduction and surgical closure
Which side of the umbilical cord does gastroschisis occur
Right
How is the bowel stopped from drying out in gastroschisis
Put in plastic bag
Exomphalos
Failure of umbilicus to close completely combined with failure of mid gut to herniate back into abdo cavity fully
Intestines inside membrane
Difference between exompahlos and gastroschisis
Exomphalos - bowel covered by membranes of umbilical cord
Why must babies with Exomphalos be delivered by c section
Membranes around bowel may burst during vaginal delivery
Cleft lip cause
Failure of maxilla to fuse with medial nasal prominence
Cleft lip
Cleft between filtrum and rest of upper lip between central and lateral incisors
Cleft palate cause
Failure of palatial shelves to fuse
