Structural heart defects Flashcards
(42 cards)
List some structural heart defects.
Ventricular septal defect Atrial septal defect Atrioventricular septal defect Tetralogy of Fallot Coarctation of Aorta Eisenmenger Syndrome
What is a structural heart defect?
A problem with the structure of the heart, rather that the muscle (cardiomyopathy) or the ion channels (Channelopathies)
What are the structural problems in Tetralogy of Fallot?
4 problems (hence Tetralogy):
- Ventricular Septal Defect
- Pulmonary Artery Stenosis
- Hypertrophy of R Ventricle
- Overriding Aorta (overrides the V septal defect)
Describe the problems that occur as a result of the structural abnormalities in ToF.
- Ventricular Septal Defect
- Pulmonary Artery Stenosis
- Hypertrophy of R Ventricle
- Overriding Aorta
Pulmonary artery stenosis (2) causes RV pressure to be higher than LV
This causes the hypertrophy of the RV (3)
It also causes deoxygenated blood to flow through the ventricular septal defect (1) from RV to LV
The aorta overrides the ventricular septal defect (4) so blood from both the RV and LV goes up it
The body does not receive very well oxygenated blood
What impact does stress have on ToF?
Stress causes more deoxygenated blood to flow from the RV to the LV through the ventricular septal defect
Causing the blood that enters the aorta to be less oxygenated (hypoxaemia)
The body becomes starved of oxygen, cyanosis
How do patients with ToF present?
Very young
Tet spells They go blue intermittently Failure to grow & thrive Dyspnoea Heart murmur Clubbing of fingers and toes
What are tet spells?
When babies with ToF suddenly get deep blue ski, nails & lips after crying or feeding or becoming stressed
Caused by a rapid drop in oxygen levels in the blood
What causes ToF?
Genetic mutations
Investigations for ToF?
Echo: best diagnostic tool, can even be done prenatally
Treatment of ToF.
Tet spells can be treated with B-blockers, or vasopressors
Surgical repair:
Patch across the ventricular septal defect, to restore a near normal circulation
When is surgical repair to treat ToF usually done?
About age 2
What’s the prognosis of patients with ToF?
Good! Often they go on to live full and active lives
They do however often get pulmonary valve regurgitation in adult life, and require surgery to resolve this
What are the structural problems in Ventricular septal defect?
An abnormal connection (hole) between the 2 ventricles
What causes a ventricular septal defect?
Congenital most of the time
Acquired: after an MI (rare)
Is ventricular septal defect common?
Yes it makes up 20% of all congenital heart defects
If you are born with a ventricular septal defect, it will always need surgical intervention to close it up.
True or false?
False
Many ventricular septal defects close on their own
Describe the problems that occur as a result of ventricular septal defect.
Pressure in LV is higher than RV
So blood flows from LV to RV
This means the RV contains more blood than it should, so the lungs get a higher blood flow than they’re used to.
Do patients go blue in ventricular septal defect?
No!
Since the lungs are not being starved of oxygen, they are getting more than they should be
Do all ventricular septal defects need repairing?
No, the small ones are asymptomatic and so they need no intervention.
What problems do you get with large ventricular septal defects?
Pulmonary hypertension
Which causes SOB, poor feeding, failure to thrive
What syndrome can occur as a result of ventricular septal defect?
Eisenenger’s Syndrome
What are the clinical signs of a large ventricular septal defect?
Small, breathless, skinny baby
Increased resp rate
Tachycardia
Cardiomegaly
Murmur
What are the signs of a small ventricular septal defect?
Loud systolic murmur
Thrill: buzzing sensation
Well grown
Normal heart rate and size
Investigations for ventricular septal defect.
ECG: normal
CXR: may show cardiomegaly
Cardiac catheter into RV would show higher than normal O2 concentrations there
