Congenital heart defects/disease

Question 1

What percentage of live births have a congenital heart defect?

Answer 1

1% - more adults now living with CHD and most live normal lives

Question 2

What is the most common cyanotic congenital heart disorder?

Answer 2

Tetralogy of fallot - 1 in 1000 live births

Accounts for 10% of all adult congenital heart disease

Question 3

What are the 4 features of tetralogy of fallot?

Answer 3

1. Ventricular septal defect
2. Pulmonary stenosis
3. Right ventricular hypertrophy
4. Aorta overrides the VSD, accepting right heart blood

Question 4

Physiology of tetralogy of fallot?

Answer 4

• 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’’

Question 5

How is tetralogy of fallot surgically repaired?

Answer 5

• 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

Question 6

Outloof for TOF?

Answer 6

• 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

Question 7

What is the most common congenital HD?

Answer 7

Ventricular septal defect

4 in 1000 live births - many close spontaneously during childhood.

Question 8

Physiology of VSD?

Answer 8

• High pressure LV, lower pressure RV
• Blood flows from LV to RV
• Babies not blue
• Increased blood flow to the lungs

Question 9

Effects of a large VSD?

Answer 9

• 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.

Question 10

What is Eisenmengers syndrome?

Answer 10

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

Question 11

Is a primum or secundum ASD most common?

Answer 11

Secundum where the hole is high in the atrial septum = 90% of cases
Primum = hole is low in atrial septum (more associated with Downs)

Question 12

Physiology of ASD?

Answer 12

• 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

Question 13

Effects of a small and large ASD?

Answer 13

• *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

Question 14

Clinical signs of ASD?

Answer 14

• 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

Question 15

What is an atrio-ventricular septal defect? How common is it?

Answer 15

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.

Question 16

Signs/symptoms of complete AVSD?

Answer 16

• Breathless as neonate
• Poor weight gain
• Poor feeding
• Torrential pulmonary blood flow
• Quickly develop Eisenmenger syndrome
• Needs repair or PA band in infancy
• Repair is surgically challenging

Question 17

What is a patent ductus arteriosus? What symptoms will the baby have?

Answer 17

Ductus arteriosus between aorta and pulmonary artery remains open after birth.
This will lead to symptoms of VSD.

Larger duct = The baby will experience high pressure in the PA coming from the aorta, increasing pulmonary HTN, increasing pressure in the RA and Eisenmenger’s syndrome. Baby will be breathless, feed poorly and fail to thrive. Needs to be closed surgically (usually percutaneously)

Question 18

What is coarctation of the aorta?

Answer 18

Narrowing of the aorta usually at the site of the insertion of the ductus arteriosus

Question 19

Symptoms of severe and mild coarctation of aorta?

Answer 19

• Complete or almost complete obstruction to aortic flow
• Collapse with HF
• Needs urgent repair

Mild:

• Kidneys feel low BP and activate RAAS and sympathetic NS → rise in BP before the narrowing (right arm, head and neck)
• Presents with HTN in right arm and head and neck early in life
• Incidental murmur
• Weak femoral arteries

Question 20

How do you repair coarctation of aorta?

Answer 20

• Surgically
• Chop the aorta and bring the 2 normal bits together
• Balloon the aorta and open it up

Question 21

Long term problems with repair of coarctation of aorta?

Answer 21

• 50-60% develop HTN
• Early CAD
• Subarachnoid haemorrhage
• Re-coarctation requiring repeat intervention
• Aneurysm formation at the site of repair (particularly in those with goretex patching)

Question 22

What risks does bicuspid aortic valve carry?

When do we perform surgery for BAV?

Answer 22

• Valves degenerate early and quicker than normal
• Can be stenotic at birth or can present during life
• Can become regurgitant earlier than normal
• 60% lifetime chance of need for surgery
• Swelling of ascending aorta related to the BAV
• Protective surgery needed for some >55mm (normal is 35mm)

Question 23

What is pulmonary stenosis?

How common is it?

Answer 23

• Narrowing of outflow of the RV
• Valvular or subvalvular or supra valvular or PA branch narrowing
• majority are narrowing of PV
• 10% of all congenital heart defects - relatively common

Question 24

Symptoms/signs of severe and mild Pulmonary stenosis?

Treatment?

Answer 24

Severe

• RV failure as neonate
• Collapse
• Poor pulmonary blood flow
• RV hypertrophy
• Tricuspid regurgitation

Mild

• Well tolerated for many years
• RV hypertrophy

Treatment

• Balloon valvuloplasty
• Open valvotomy
• Open trans-annular patch
• Shunt to bypass blockage if the PA hasn’t grown much (rare)

Question 25

What is a univentricular heart? What is the fontan procedure? Effects on patient?

Answer 25

Hearts with only 1 usable ventricle, lacking 2 functional fully developed ventricles. Use the ventricle you have, attach to aorta, close PA if open, PA into superior vena cava = fontan circuit Effects on patient - Patients appear pink - Reduced exercise capacity - Long term complications and risks from a passive venous circuit - Uncertain long term as this surgery hasn't been around for a very long time (60% at age 40)