Congenital CV Abnormalities - Severson

Question 1

What is ectopia cordis, and what is believed to cause this condition?

Answer 1

• congenital malformation in which the heart is abnormally located either partially or totally outside of the thorax
  
  • due to failure in folding of the lateral body wall and its meeting with the cephalic fold

Question 2

How does the dextrocardia develop?

Answer 2

• abnormal folding of the embryonic heart

Question 3

What developmental structures and events are responsible for an Atrial Septal Defect?

Answer 3

• Excessive resorption of 1° septum
• Incompetent foramen ovale
  
  • due to hypoplastic growth of 2° septum
• Inadequate development of the primary septum
  
  • produces basal opening
• Sinus venosus development defect

Question 4

How do Atrial Septal Defects (ASDs) manifest after birth?

Answer 4

• Left → Right shunting
• increased pulmonary flow
  
  • only large ones lead to pulmonary hypertension with cyanosis tardive and cardiac failure
• Right ventricular failure
• Paradoxical embolism

Question 5

What developmental abnormalities occur in ventricular septal defects (VSD)? How are they clinically manifested?

Answer 5

• 90% due to malformation of membranous portion of ventricular septum
• Muscular septum involvement may exhibit multiple sites
  
  • swiss-cheese septum

Question 6

How are Ventricular Septal Defects clinically manifested?

Answer 6

• Size dependent
• Pulmonary stenosis
• Murmur
• Cyanosis tardive in long-standing cases

Question 7

What is the role of the bulbar/truncal ridges (aorticopulmonary septum) in the development of Persistent Truncus Arteriosus?

Answer 7

• complete developmental failure of the bulbar & truncal ridges
  
  • aorticopulmonary septum never forms

Question 8

What is the role of the bulbar/truncal ridges (aorticopulmonary septum) in the development of Transposition of the Great Arteries?

Answer 8

• failure of the normal spiraling of the aorticopulmonary spetum

Question 9

What is the role of the bulbar/truncal ridges (aorticopulmonary septum) in the development of Tetralogy of Fallot?

Answer 9

• anterior malalignment of the aorticopulmonary septum
• causes tetrad of abnormalities
  
  • VSD
  • pulmonary stenosis (tiny pulmonary trunk)
  • overriding (large) aorta
  • right ventricular hypertrophy develops progressively from resistance to blood flow through the right ventricular outflow tract.

Question 10

What are the two types of Coarctation of the Aorta that can occur?

Answer 10

• Postductal (adult form)
  
  • 95%
  • 2xMales vs. females
• Preductal (infantile form)

Question 11

What are the clinical manifestations of a Postductal Coarctation of the Aorta?

Answer 11

• Increased BP in arms
• Decreased BP in legs
• Notched ribs
  
  • enlarged intercostal/interthoracic arteries
• Weak pulses in lower limbs
• Complications:
  
  • CHF
  • CVA
  • rupture
  • infection

Question 12

What are the clinical manifestations of a Preductal Coarctation of the Aorta?

Answer 12

• Patent ductus arteriosus
• Early CHF due to hypertrophy of R. ventricle
• Cyanosis in lower half of body

Question 13

What clinical situations may prevent closure of the Ductus Arteriosus?

Answer 13

• Transposition of the Great Arteries
• Pulmonary stenosis & Atresia (orifice closed)
• Coarctation of Aorta
• Aortic stenosis, & Atersia
• Preterm birth (lungs not developed)
• Congenital Rubella Syndrome
• Down Syndrome

Question 14

How might a Patent Ductus Arteriosus be treated?

Answer 14

• Premies/Newborns:
  
  • Indomethacin up to 1 week
• 1+ week Postnatal:
  
  • Surgery with catheter-placed occluder

Question 15

What are the clinical features of Patent Ductus Arteriosus?

Answer 15

• “Machine-like” murmur
• Maternal rubella (german measles) during early weeks of pregnancy
• Infectious endocarditis
• Pulmonary hypertension
• Slightly enlarged liver

Question 16

What cardiac abnormalities are associated with Right-to-Left shunts?

Answer 16

• Tetralogy of Fallot
• Transposition of the Great Arteries
• Truncus Arteriosus

(“Blue babies” take take take oxygen right away!)

Question 17

What cardiac abnormalities are associated with Left-to-Right Shunts?

Answer 17

• Atrial Septal Defect
• Ventricular Septal Defect
• Patent Ductus Arteriosus

(late cyanosis = “blue kids”)

Question 18

What developmental structure is responsible for the occurrence of either pulmonary or aortic stenosis?

Answer 18

Defective development of aorticopulmonary septum (bulbar-truncal ridges)