Tetralogy Of Fallot

Question 1

What type of condition is TOF

Answer 1

Congenital - present at birth

Question 2

What can a heart murmur be caused by?

Answer 2

Turbulent flow through the heart:
- narrow valve - stenosis
- leaky valve - regurgitation
- hole in heart - atrial or ventricular septal defect

Question 3

What is a ventricular septal defect ?

Answer 3

Allows deoxygenated blood to mix with oxygenated blood as a hole in the septum of the ventricles
- congenital
- or acquired (eg: after a heart attack)

Question 4

What are the impacts of a VSD on blood flow, pressure, and oxygenation

Answer 4

1. Oxygenated and deoxygenated blood mixed
2. Pulmonary circuit increase in pressure
3. Right ventricular hypertrophy

Question 5

What are the 4 features of tetralogy of fallot?

Answer 5

• pulmonary stenosis (valve narrowing)
• overriding aorta (aorta opening lies over lest ventricle and VSD)
• R ventricular hypertrophy
• VSD

Question 7

What colour can babies turn in fallots tetralogy

Answer 7

Blue - cyanosis
- discolouration of the skin and mucous membranes
- low oxygen sats in the tissues
- may be due to hypercyanotic attack

Question 8

Hypercyanotic attack meaning

Answer 8

Acute hypoxia episode
- may result in hypoxic brain injury and death
- SoB, cyanosis, agitation, light headedness, loss of consciousness

Question 9

Hypertonic attack - why is it happening?

Answer 9

Shift of deoxygenated blood to oxygenated blood which is then going to the systemic circulation:
- right to left shunt due to increased parasympathetic tone - eg from crying or bowel movement
- decreased vascular resistance in the systemic circuit = lower pressure = explaining the shunt

Can cause HYPER cyanosis

Question 10

What may children do to relive symptoms in hypercyanotic attack?

Answer 10

Squat

• increases systemic vascular resistance
• reduces the shunt
• promoting more blood going to the lungs and getting oxygenated

Question 11

What other symptoms can tetralogy of fallot cause

Answer 11

• difficulty feeding
• failure to gain weight
• delayed growth and physical development

Question 12

How is ToF diagnosed

Answer 12

• echocardiology - ultrasound of the heart

Question 13

What is surgical treatment for ToF

Answer 13

• 6 months old
• less than 5% perioperative mortality
• repair of right ventricular outflow tract (may stretch out or place material in pulmonary artery) and pulmonary stenosis - excess muscle removed
• repair of VSD

Hypertrophy of RV will go down over time

Question 14

What happens if ToF is untreated?

Answer 14

• rapid RV hypertrophy
• could become heart failure
• 35% mortality in first year of life - 50% in next 2 years

Question 15

What is a downside to total surgical repair for ToF

Answer 15

• progressively leaky pulmonary vaulted may develop in later adulthood