Lecture 7- Congenital heart defects

Question 1

congenital heart defects prevalence

Answer 1

most common birth defect (1% incidence)

Question 2

surival rate of CHD

Answer 2

90% survive to adulthood

most common cause of indirect maternal death

Question 3

when does CHD occur

Answer 3

Occurs when there is

Question 4

what is the developing heart vulnerable to

Answer 4

Developing heart vulnerable to the same things as other systems e.g. teratogenic agents

Question 5

ventral septal defect (VSD)

Answer 5

• During development of the interventricular septum, the membranous portion of the septum fails to develop properly- primary interventricular foramen remains open
• Blood in left ventricle will flow into the right ventricle
• Will eventually caused right sided heart failure

Question 6

Patent ductus arteriosus (PDA)

Answer 6

Is a persistent opening between the two major blood vessels leading from the heart. The opening, called the ductus arteriosus, is a normal part of a baby’s circulatory system before birth that usually closes shortly after birth. If it remains open, however, it’s called a patent ductus arteriosus.

–> blood continues to shunt from left to right

Question 7

Atrial septal defect (ASD)

Answer 7

• Under development of the septum primum or secundum
• Allows blood in the left atrium to flow into the right atrium
• Increased vol in RA leads to higher volume being pumped around pulmonary circulation damage pulmonary vasculature an fibrosis of arteries in the lungs (if left untreated)

Question 8

Aortic/ pulmonary stenosis

Answer 8

• One or both semilunar valves (triscuspid (all are tricuspid accept mitral- bicuspid) don’t develop properly when the baby is born
  
  • E.g. only having two leaflets
• Results in left/right ventricular hypertrophy as the heart is having to generate more force to push blood through the stenosed valves  leads to heart failure

Question 9

Hypoplastic left heart syndrome

Answer 9

Left heart doesn’t develop fully.

• Inadequate right to left flow inadequate in utero
• Use it or lose it rule applies** left heart underdeveloped

Question 10

Tetralogy of Fallot

Answer 10

Characterised by four defects that present together

Question 11

four defects that present together in the tetralogy of fallot

Answer 11

pulmonary stenosis

overriding aorta

ventricular spetal defect

hypertrophy of the right ventricle

Question 12

• Pulmonary Stenosis

Answer 12

the pulmonary artery or the pulmonary valve is narrowed, so less blood can enter–> leads to right sided hypertrophy –> right sided heart failure

Question 13

Ventricular Septal Defect

Question 14

overriding aorta

Answer 14

aorta is large (larger than the pulmonary artery) and situated right next to the VSD so most of the blood in the heart flows through it.

Question 16

hypertrophy of the right ventricle

Answer 16

due to pulmonary stenosis

• heart tried to generate more force to pump the blood throguh the stenosis

Question 17

transposition of the great arteries

Answer 17

The aorticopulmonary septum forms, but does not spiral, therefor when the baby is born the aorta arises from the right ventricle and the pulmonary from the left ventricle

• The pulmonary and systemic circulations are almost separate, with only an ASD and PDA allowing some oxygenated blood to enter the systemic circulation.

Question 18

transposition of the great arteries prognosis and treatment

Answer 18

• This is a neonatal emergency and prostaglandins must be given to the baby quickly in order to maintain the PDA and allow some oxygenated blood into the systemic circulation until surgery can be performed.