CVS 4 Congenital Heart Disease

Question 1

Causes of congenital heart diseases

Answer 1

Genetics
Environment- teratogenicity from drugs + alcohol
Maternal infections

Question 2

What is teratogenicity?

Answer 2

Agent which causes malformation of embryo

e.g. drugs + alcohol whilst pregnant

Question 3

What are some genetic conditions which have a higher chance of congenital heart disease?

Answer 3

Down’s syndrome
Tuner’s syndrome
Marfan’s syndrome

Question 4

Two types of congenital heart defects

Answer 4

Acyanotic
Cyanotic

Question 5

What is the shunt in acyanotic CHD?

Answer 5

Left to right shunt
Blood in system system fully saturated
pO2 is maintained

Question 6

What is the shunt in cyanotic CHD?

Answer 6

Right to left
Blood mixing > deoxygenated blood in systemic circulation
Decrease in pO2

Question 7

Physical presentation of cyanotic CHD?

Answer 7

Blue discolouration of skin + lips

Question 8

What causes an atrial septal defect?

Answer 8

• Opening in wall between atria - foramen ovale
• Due to underdevelopment of septum primum or secundum
• Hole between atria

Question 9

What is caused by underdevelopment of septum primum or secundum?

Answer 9

Atrial septal defect

Question 10

What is the shunt in ASD?
What is the effect?

Answer 10

L > R shunt
Increased pulmonary blood volume > damage to vasculature > resistance > pulmonary hypertension (rare) > pulmonary oedema due to fluid forced out
Right side heart failure

Question 11

What can happen in ASD if pulmonary hypertension is left untreated?

Answer 11

RA pressure > LA pressure
R > L shunt
Mixing of blood - cyanotic
Eisenmenger’s syndrome

Question 12

What causes a ventricular septal defect?

Answer 12

Primary interventricular foramen remains open
Septum doesn’t develop properly
Hole between ventricles

Question 13

What is caused by undevelopment of the septum?

Answer 13

Ventricular septal defect

Question 14

What is the shunt in VSD?
What is the effect if left untreated?

Answer 14

L > R shunt
Pulmonary hypertension
Right sided heart failure

Question 15

What is the cause of an atrioventricular septal defect?

Answer 15

Failure of endocardial cushion development
Holes between atria + ventricles

Question 16

What condition is AVSD common in?

Answer 16

Down’s syndrome

Question 17

What CHD is common in Down’s syndrome?

Answer 17

Atrioventricular septal defect

Question 18

What is the shunt in AVSD?

Answer 18

L > R shunt

Question 19

What causes aortic/pulmonary stenosis?

Answer 19

Semilunar valves don’t develop properly - narrow when born

Question 20

What is the common defect in the aortic valve in aortic stenosis?

Answer 20

2 leaflets instead of 3

Question 21

What can aortic/pulmonary stenosis causes?

Answer 21

• Heart has to work harder to push blood through stenosed valves
• Ventricular hypertrophy
• Heart failure

Question 22

What is the cause of coartication of aorta?

Answer 22

Congenital narrowing of aorta

Question 23

Common site of coartication of aorta

Answer 23

Ductus arteriosus area

Question 24

Presentation of coartication of aorta

Answer 24

Radial-femoral delay
Strong radial pulse
Weak femoral pulse

Question 25

Presentation of coartication of aorta if narrowing is between brachiocephalic + left subclavian artery

Answer 25

Radial-radial pulse delay Delay in both wrists

Question 26

Effect of coartication of aorta

Answer 26

- Increased pressure upstream - Increased risk of aneurysms of aortic arch - Increased risk of aortic root dilation > aortic valve regurgitation

Question 27

What is aortic valve regurgitation?

Answer 27

Aortic valve doesn’t close properly

Question 28

What is the cause of patent ductus arteriosus?

Answer 28

Ductus arteriosus remains open after birth

Question 29

What happens in PDA? What are the effects?

Answer 29

Ductus arteriosus doesn’t close after first breath Blood flows from aorta to PA - acyanotic Increased volume in PA > increased afterload for RV Right sided heart failure

Question 30

What is the cause of tricuspid atresia?

Answer 30

Tricuspid valve fails to form

Question 31

What is the effect of tricuspid atresia? What other CHDs do babies with TA have?

Answer 31

- Blood cant flow form RA > RV - Babies have **ASD** + **VSD** to allow blood into pulmonary circulation - ASD - R > L shunt of all venous return - VSD - allows blood into RV + out through PA - Blood mixing > **central cyanosis**

Question 32

What is the cause of pulmonary atresia?

Answer 32

Pulmonary valve fails to form

Question 33

What other CHDs are in babies with pulmonary atresia?

Answer 33

**VSD** - deoxygenated blood RV > LV **PDA** - lows blood to pulmonary circulation

Question 34

What is given to newborns in transposition of great arteries before surgery to keep them alive?

Answer 34

Prostaglandins

Question 35

What causes transposition of great arteries?

Answer 35

Aorticopulmonary septum forms but doesn’t spiral RV connected to aorta LV connected to pulmonary artery

Question 36

What are the 4 defects in the tetralogy of fallot?

Answer 36

**POSH** **P**ulmonary stenosis **O**verriding aorta **S**eptal defect (ventricular) **H**ypertorphy of RV

Question 37

Why is there hypertrophy of RV in tetralogy of fallot?

Answer 37

To compensate for stenosis in PA

Question 38

What causes a hypoplastic heart?

Answer 38

Underdevelopment of left ventricle Due to mitral or aortic valve stenosis in utero

Question 39

Effect of hypoplastic heart

Answer 39

R > L shunt **cyanotic** Small ascending aorta if aortic valve is stenosed

Question 40

What CHDs are in patients with hypoplastic heart?

Answer 40

**ASD** + **PDA** ASD - allow oxygenated blood to flow to PA PDA - allows this blood into aorta to systemic system

Question 41

What causes univentricular heart?

Answer 41

Ventricular septum doesnt form at all

Question 42

What does failure of ventricular septum formation cause?

Answer 42

Univentricular heart

Question 43

What does underdevelopment of the left ventricle cause?

Answer 43

Hypoplastic heart

Question 44

What does the lack of spiralling of the aorticopulmonary septum cause?

Answer 44

Transposition of great arteries

Question 45

What does failure of pulmonary valve formation cause?

Answer 45

Pulmonary atresia

Question 46

What does failure of the tricuspid valve formation cause?

Answer 46

Tricuspid atresia

Question 47

What does failure of the ductus arteriosus closing after birth cause?

Answer 47

Patent ductus arteriosus

Question 48

What does narrowing of the aorta cause?

Answer 48

Coartication of aorta

Question 49

What does underdevelopment of the semilunar valves cause?

Answer 49

Aortic/pulmonary stenosis

Question 50

What does failure of the endocardial cushion development cause?

Answer 50

Holes between atria + ventricles Atrioventricular septal defect

Question 51

What does underdevelopment of the septum cause?

Answer 51

Ventricular septal defects

Question 52

What condition occurs if the primary interventriclar foramen remains open?

Answer 52

Ventricular septal defects

Question 53

What defect is most likely if a newborn baby has continuous murmur + no signs of cyanosis?

Answer 53

Patent ductus arteriosus

Question 54

What defect is most likely if a newborn baby has a loud systolic murmur in left sternal border + no signs of cyanosis?

Answer 54

Ventricular septal defect

Question 55

List the acyanotic congenital heart defects

Answer 55

- atrial septal defect - ventricular septal defect - atrioventricular septal defect - aortic/pulmonary stenosis - coartication of aorta - patent ductus arteriosus

Question 56

List the cyanotic congenital heart defects

Answer 56

- tetralogy of fallot - tricuspid/pulmonary atresia - transposition of great arteries - uni ventricular heart - hypoplastic heart