Congenital heart abnormalities

Question 1

what are congenital cardiac abnormalities associated with?

Answer 1

chromosomal abnormalities

Question 2

what causes congenital cardiac defects?

Answer 2

chromosomal abnormalities
teratogens
mostly multi-factorial complex interplay between genetic and environmental factors
maternal disease - such as diabetes

Question 3

embryological origin of heart

Answer 3

heart tubes from lateral plate mesoderm

Question 4

when do heart tubes begin to form?

Answer 4

4th week of development

single primitive heart tube forms and then week 5-8 it septates

Question 5

when does the heart begin to beat?

Answer 5

day 22 of development

Question 6

when does blood begin to circulate?

Answer 6

day 24 of development

Question 7

what causes vascular abnormalities?

Answer 7

failure of remodelling

Question 8

right sided aortic arch

Answer 8

due to involution of left aortic arch and failure of involution of right aortic arch

Question 9

persistence of both primitive aortic arches

Answer 9

results in vascular ring encircling the oesophagus and trachea, potentially constricting these and causes breathing difficulties or dysphagia

Question 10

foramen ovale

Answer 10

between atria in fetal heart

Question 11

ductus arteriosus

Answer 11

between pulmonary circulation and aorta in fetal heart

Question 12

what forms the outflow tract of ventricles?

Answer 12

conus cordis

Question 13

abnormalities of lateralisation

Answer 13

reversal of direction of heart tube folding

Question 14

what are abnormalities of lateralisation?

Answer 14

dextrocardia
situs inversus
levocardia

Question 15

dextrocardia

Answer 15

heart on right but abdominal contents are normally positioned (situs solitus) discordance between viscera and so there are often cardiac abnormalities, such as atrioventricular discordance, septal defects, single ventricle, transposition of great arteries, anomalous pulmonary venous return

Question 16

situs inversus

Answer 16

reversal of laterality of thoracic and abdominal organs

• concordance between reversal of laterality can mean patients are asymptomatic
• patients with situs inversus not particularly at increased risk of cardiac defects but increased chance of pulmonary disease

Question 17

Kartagener’s syndrome

Answer 17

disorder of ciliary motility:
chronic sinusitis 
nasal polyposis 
bronchiectasis 
risk in situs inversus

Question 18

levocardia

Answer 18

normal thoracic viscera positioning
reversed abdominal contents positioning
rarer
discordance means there are congenital defects in 95% of patients

Question 19

what forms the vena cava?

Answer 19

sinus venosus

becomes incorporated into right atrium

Question 20

what forms the pulmonary veins?

Answer 20

left atrium

Question 21

crista terminalis

Answer 21

border between trabeculated and smooth walled part of right atrium

Question 22

left atrial appendage

Answer 22

primitive left atrium

Question 23

when does atrial septation occur?

Answer 23

week 4 and onwards

Question 24

what divides the common primitive atria?

Answer 24

septum primum and septum secondum

Question 25

how is the foramen ovale formed?

Answer 25

opening left by septum secondum

Question 26

what is the foramen ovale?

Answer 26

shunt from right to left atrium

Question 27

fossa ovalis

Answer 27

closure of foramen ovale | can be seen on medial wall of right ventricle

Question 28

what causes an ASD?

Answer 28

failure of formation of atrial septa

Question 29

what causes a patent foramen ovale?

Answer 29

failure of fusion of septum primum and secondum = PFO

Question 30

ASD prevalence

Answer 30

10% of congenital cardiac defects

Question 31

ASD

Answer 31

continuous left to right shunting of blood impacts right side of heart risk of paradoxical embolus

Question 32

Paradoxical embolus in PFO

Answer 32

thrombus passing between venous and arterial circulation | indication for closure of PFO

Question 33

PFO

Answer 33

common present in 20-30% of population often asymptomatic

Question 34

risks of PFO

Answer 34

paradoxical embolus if right atrial pressure exceeds left side in pulmonary disease

Question 35

atrioventricular canal defect

Answer 35

failure of formation of endocardial cushions affects all chambers of heart can be associated with chromosomal abnormalities, specifically trisomy 21

Question 36

atrioventricular canal defect

Answer 36

frequent communication between sides of the heart increased right sided heart pressure pulmonary hypertension heart failure can cause recurrent respiratory tract infections

Question 37

when is the ventricular septum formed?

Answer 37

end of week 4

Question 38

formation of interventricular septum

Answer 38

involves neural crest cells

Question 39

trabeculated part of right ventricle

Answer 39

bulbus cordis

Question 40

trabeculated part of left ventricle

Answer 40

common primitive ventricle

Question 41

what causes VSD?

Answer 41

failure of formation of ventricular septum | most common congenital cardiac abnormality in children and 2nd most common in adults

Question 42

which part is most commonly affected in VSD?

Answer 42

membranous part of ventricular septum

Question 43

VSD symptoms

Answer 43

vary depending on severity and size | can be asymptomatic if there is minimal shunting or can show symptoms of heart failure

Question 44

what are the symptoms of heart failure?

Answer 44

``` hepatomegaly failure to thrive exertional dyspnoea raised JVP peripheral oedema ```

Question 45

mitral valve

Answer 45

anterior and posterior cusps

Question 46

tricuspid valve

Answer 46

anterior, posterior and septal cusps

Question 47

what forms the aortic and pulmonary trunks?

Answer 47

truncus arteriosus

Question 48

neural crest cells

Answer 48

influence development of cardiac septa and outflow tracts

Question 49

failure of formation of conotruncal septa

Answer 49

results in persistent truncus arteriosus

Question 50

persistent truncus arteriosus

Answer 50

single blood vessel carrying blood from heart to systemic, pulmonary and coronary circulations always associated with VSD

Question 51

how does persistent truncus arteriosus present?

Answer 51

congestive heart failure | cyanosis

Question 52

what causes transposition of great vessels?

Answer 52

failure of correct formation of conotruncal septa

Question 53

transposition of great vessels

Answer 53

aorta arises from right ventricle and pulmonary outflow tract arises from left ventricle

Question 54

transposition of great vessels presentation

Answer 54

within 24 hours | cyanosis

Question 55

tetralogy of fallot

Answer 55

pulmonary infundibular stenosis, VSD, overriding aorta and right ventricular hypertrophy (develops after birth)

Question 56

tetralogy of fallot presentation

Answer 56

cyanosis | right to left shunting of blood

Question 57

transition to post-natal circulation

Answer 57

at birth pulmonary vascular resistance falls and blood circulates through lungs patent ductus arteriosus and foramen ovale close forming ligamentum arteriosum and fossa ovalis

Question 58

failure of closure of foramen ovale

Answer 58

PFO

Question 59

failure of closure of ductus arteriosus

Answer 59

= patent ductus arteriosus, in some circumstances can be necessary to preserve life where there is structural heart disease, e.g. tetralogy of fallot - patent ductus arteriosus symptoms vary depending on size

Question 60

presentaation of patent ductus arteriosus

Answer 60

if large can present within 1 year of birth failure to thrive breathing difficulties small one may not present until adulthood

Question 61

uncorrected patent ductus arteriosus

Answer 61

can lead to pulmonary hypertension and right sided heart failure