Structural heart defects Flashcards
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
Management for ventricular septal defect.
Medical initially: check if hole will close up itself
If not surgical intervention
What are the structural problems in atrial septal defect?
There are 2 types.
A hole connecting the two atria
Ostium secundum: hole is high in septum
Ostium primum: hole is low in septum
What is the problem with Ostium primum atrial septal defects?
The hole often interferes with the AV valves… so more problems arise
When do each type of atrial septal defect present?
Why?
Primum: early in life
Secundum: later in life, 40-60, the severity of the L-R shunt depends on how well the ventricles are working, later in life they become less efficient so the L-R shunt causes more problems
Describe the problems that result from atrial septal defect?
L to R shunt
Blood flows from the left to the right atria
What are the clinical features of atrial septal defect?
Atrial fibrillation
Raised JVP
Pulmonary ejection systolic murmur
Pulmonary hypertension
Increased frequency of migraines
Investigation of atrial septal defect.
Echo
Management of atrial septal defect.
Closure before age 10
What structural problems do you get in atrioventricular septal defects?
A hole in the centre of the heart abnormally joining all of the heart chambers together
What genetic disorder is associated with atrioventricular septal defect?
Down’s syndrome
Clinical features of atrioventricular septal defect.
Difficulty breathing (dyspnoea)
Cyanosis
Signs of heart failure such as oedema, fatigue, wheezing, sweating and irregular heartbeat
Investigations of atrioventricular septal defect.
Auscultation: there are murmurs and sounds characteristic of atrioventricular septal defect
Echo
Management of atrioventricular septal defect.
Close the hole
What is Eisenmengers Syndrome?
When high pressure pulmonary blood flow caused by a septal defect results in damage to the delicate pulmonary vasculature
What happens as a result of Eisenmengers syndrome?
Damage to pulmonary vasculature causes increased resistance to blood flow through the lungs
This means the pressure in the RV builds up due to backlog created by resistance
Raised RV pressure means that the shunt reverses and blood goes from R to L.
The LV fills with deoxygenated blood, the body receives this blood so becomes starved of oxygen
What are the clinical features of Eisenmengers syndrome?
Blue! Cyanosis
Heart failure Fainting Abnormal heart rhythms Bleeding disorders Coughing up blood Iron deficiency Infections (endocarditis and pneumonia) Kidney problems Stroke
What conditions can lead to Eisenmengers syndrome?
Ventricular septal defect
Atrial septal defect
What is the prognosis after developing Eisenmengers syndrome?
Poor
