CVS S3.5 - Congenital heart defects

Question 1

What is ASD?

Answer 1

Atrial septal defect

Opening between the two atria in the intertribal septum which persists after birth

Question 2

In which direction would blood flow through an atrial septal defect?

Answer 2

• Left to right due to slightly higher pressure in left atrium than right atrium (acyanotic)

Question 3

What are the two most common sites for an atrial septal defect?

Answer 3

• Foramen ovale

- Ostium primum in the inferior portion of the septum

Question 4

What is a VSD and where does it most commonly occur?

Answer 4

• Ventral septal defect; opening between the two ventricles in the interventricular septum
• Most commonly in the membranous portion

Question 5

What is a patent ductus arteriosus?

Answer 5

Failure of ductus arteriosus to close after birth causing blood flow from the aorta to the pulmonary artery

Left to right shunt - acyanotic

Question 6

What is Eisenmenger syndrome?

Answer 6

• Occurs as a result of patent ductus arteriosus
• Increase in pulmonary resistance beyond systemic circulation causes reverse of blood flow (normally left to right shunt but is reversed)

Question 7

What is coarction of the aorta and where does it most commonly occur?

Answer 7

Narrowing of the aortic lumen in the region of the ligamentum arteriosus

Question 8

How does blood supply change as a result of coarction of the aorta?

Answer 8

Vessels to the head and upper limb branch proximal to coarction so are unaffected but blood supply to the rest of the body is reduced

Question 9

How would coarction of the aorta be detected clinically?

Answer 9

• Weak and delayed femoral pulse

- Upper body hypertension

Question 10

What is Tetralogy of Fallot

Answer 10

• A congenital heart defect that classically involves four anatomical abnormalities of the heart
• It is the most common cyanotic heart defect and the most common cause of blue baby syndrome

Question 11

What four lesions make up Tetralogy of Fallot

Answer 11

• Ventral septal defect
• Pulmonary stenosis
• Overriding aorta (An overriding aorta is a congenital heart defect where the aorta is positioned directly over a ventricular septal defect (VSD), instead of over the left ventricle)
• Right ventricular hypertrophy

Question 12

Why is tetralogy of fallot a cyanotic heart defect?

Answer 12

• Pulmonary stenosis causes persistent right ventricular hypertrophy
• Coupled with the presence of a VSD and overriding aorta, blood is able to flow from right to left
• Mix of oxygenated and deoxygenated blood enters the systemic circulation

Question 13

What is required in tricuspid atresia to ensure the right to left shunt of blood flow (needed to survive, otherwise fatal)

Answer 13

ASD or PFO

and

VSD or PDA

to allow blood flow to the lungs which would otherwise not happen

Question 14

What changes occur from normal circulation in transposition of the great arteries?

Answer 14

• Pulmonary artery connects to the left ventricle
• Aorta connects to the right ventricle
• Two unconnected parallel circulations set up opposed to two circulations in series

Question 15

What two structures are not properly developed in hypoplastic left heart?

Answer 15

Left ventricle and ascending aorta

Question 16

How is blood supplied to the systemic circulation on hypo plastic left heart?

Answer 16

Via PDA

PTO or ASD also present

Question 17

List the acyanotic congenital heart defects (Left to right shunts)

Answer 17

• Atrial septal defects
• Patent foramen ovale
• Ventricular septal defects
• Patent ductus arteriosus

Question 18

List the cyanotic congenital heart defects (Right to left shunts)

Answer 18

• Tetralogy of Fallot
• Tricuspid Atresia
• Transposition of the great arteries
• Hypoplastic left heart