Congenital heart defects/disease Flashcards
What percentage of live births have a congenital heart defect?
1% - more adults now living with CHD and most live normal lives
What is the most common cyanotic congenital heart disorder?
Tetralogy of fallot - 1 in 1000 live births
Accounts for 10% of all adult congenital heart disease
What are the 4 features of tetralogy of fallot?
- Ventricular septal defect
- Pulmonary stenosis
- Right ventricular hypertrophy
- Aorta overrides the VSD, accepting right heart blood
Physiology of tetralogy of fallot?
- The stenosis of the RV outflow = RV at higher pressure than the left
- Blue blood passes from RV to LV
- Patients are blue ‘‘fallot spells - deep spells of cyanosis causing blackouts’’
How is tetralogy of fallot surgically repaired?
- Now most are ‘complete repairs’ where the septal defect is patched and the pulmonary outflow tract is opened by 3-6 months old
- Survival is now close to normal with the complete repair operation but there are still long term effects
Outloof for TOF?
- Mostly they do well
- Often they can get pulmonary valve regurgitation causing RV dilation in adult life and require surgery
- Arrhythmias can also be an issue
At 35 years old
- 40% have pulmonary valve replacement
- 5% ventricular tachycardia
- 5% implantable cardiac defibrillator
- 15% supraventricular tachycardia
- There is a small sudden death risk and ongoing endocarditis risk
What is the most common congenital HD?
Ventricular septal defect
4 in 1000 live births - many close spontaneously during childhood.
Physiology of VSD?
- High pressure LV, lower pressure RV
- Blood flows from LV to RV
- Babies not blue
- Increased blood flow to the lungs
Effects of a large VSD?
- Very high pulmonary blood flow in infancy
- small, breathless, poor feeding, failure to thrive
- tachycardic and big heart on cxr
- this requires fixing in infancy as they can go in HF
- It can lead to irreversible pulmonary htn and Eisenmengers syndrome where they are constantly blue.
What is Eisenmengers syndrome?
If the VSD if not fixed early:
- LV→ RV shunt causes pulmonary htn
- Pulmonary htn → increases pressure in RV
- RV pressure now exceeds LV pressure
- Shunt is reversed
- RV deoxygenated blood is pushed into LV and pumped around the circulation
- Patient becomes blue as deoxygenated blood is pumped around the circulation
- These patients have a much worse outlook
- 2 x risk of endocarditis
- higher risk of stroke
- problems with pregnancy
- poor exercise capacity
- 50% dead by about 40
Is a primum or secundum ASD most common?
Secundum where the hole is high in the atrial septum = 90% of cases
Primum = hole is low in atrial septum (more associated with Downs)
Physiology of ASD?
- Slightly higher pressure in LA than RA
- Shunt is left → right
- Recirculation of blood to the lungs
- NOT blue
- Increased flow to right heart and lungs
Effects of a small and large ASD?
- *Small**
- Small increase in flow
- No right heart dilatation
- No symptoms
- Leave alone and not intervene
- During middle age, if HTN develops → stiffening of LV → LA pressure rises → shunt is increased so effects are worsened so we do close if we see any ASD in infancy
- *Large**
- Significant blood flow through right heart and lungs in childhood
- Right heart dilatation
- SOBOE
- Increased chest infections
Clinical signs of ASD?
- Pulmonary flow murmur
- Fixed split second heart sound (delayed closure of PV because more blood has to get out)
- Big pulmonary arteries on CXR
- Cardiomegaly due to LA enlargement
What is an atrio-ventricular septal defect? How common is it?
A hole in the very centre of the heart and involves the ventricular septum, atrial septum, mitral and tricuspid valves
2 per 10,000 births
Can be complete or partial
Instead of 2 separate AV valves, there is 1 big malformed one.