7 Congenital Heart Defects Flashcards
What 3 main causes of congenital heart defects?
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Genetic:
- Down’s, Turner’s, Marfan’s
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Environmental:
- Teratogenic drugs/alcohol
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Maternal Infections:
- Rubella
What’s the difference between acyanotic and cyanotic congenital heart defects?
Acyanotic: Pink eg coarctation of aorta
Cyanotic: Blue eg less than normal levels of O2
Fill in the missing labels:
Name some acyanotic defects. (4)
- Atrial septal defect (ASD)
- Patent foramen ovale (PFO)
- Ventricular septal defect (VSD)
- Patent ductus arteriosus (PDA)
- Coarctation of Aorta
Name some Cyanotic congenital heart defects.
- Tetralogy of Fallot
- Tricuspid atresia
- Transposition of the Great Arteries
- Hypoplastic left heart
What’s the pathophysiology of an Atrial Septal Defect (ASD)?
Opening in septum between 2 atria
LA pressure= higher than right
–> oxygenated blood enters deoxygenated blood
RV volume overload- increase pulmonary blood flow
Can cause right heart failure
What is Patent foramen ovale?
PFOs may be present in up to 20% of the population.
Why are they usually clinically silent?
Higher LA pressure- causes functional closure of flap valve
What is the pathophysiology of a ventricular septal defect?
- Abnormal opening in interventricular septum
- Most commonly in membranous portion
- LV pressure > RV pressure
What is the pathophysiology of patent ductus arteriosus?
- Failure to close shunt between pulmonary artery to aorta
What is the pathophisiology of coarctation of the heart?
- Narrowing of aortic lumen
- At point of former ductus arteriosus
- Increased afterload on LV
- LV hypertrophy
- Will affect blood supply to all regions except:
- Upper and lower limbs
What are some potential problems associated with patent foramen ovale?
- Headaches/migraines
- Stroke
- TIA (transient ischaemic heart attack)
What is Eisenmenger’s syndrome?
Obstructive pulmonary vascular disease
Develops as a consequence of a large pre-existing left-to-right shunt
Causing pulmonary artery pressures to increase and approach systemic levels
Such that the direction of blood flow then becomes bi-directional or right-to-left.
How might a patient with coarctation of the heart present in terms of pulses and blood pressure?
Pulses may be:
- reduced in amplitude
- delayed between upper and lower limbs
Blood pressure:
- Higher in upper limbs compared to lower limbs
What is the pathophisiology of tetralogy of fallot?
- Group of 4 lesions
- Occur together due to single developmental defect
- Outflow portion of IV septum= too far in:
- Anterior direction
- Cephalad direction
What are the 4 abnormalites of tetralogy of fallot?
What happens as a result of these abnormalities?
- Overiding aorta
- Ventricular septal defect
- Pulmonary stenosis
- Right ventricular hypertrophy (due to pulmonary stenosis)
- Right to left shunting
- Mixing deoxygenated blood with oxygenated
- Cyanosis
What is the pathophysiology of tricuspid atresia?
Lack of developement of tricuspid valve
No inlet to right ventricle
Must have:
- ASD/PFO
- VSD/PDA
What is the pathophysiology of ‘Transposition of the great arteries’?
Two unconnected parallel circulations
Defect:
right ventricle - connected to aorta
left ventricle- connected to pulmonary trunk
What is the pathophysiology of a ‘hypoplastic left heart?
- Left ventricle and ascending aorta fail to develop properly
- PFO/ASD=present
- Blood supply to systemic circulation= via PDA
(Lethal without surgical correction)
