Fallot's Tetralogy

Question 1

Which anatomical structures are affected by Fallot’s Tetralogy?

Answer 1

1. ventricular septum
2. pulmonary valve
3. aorta
4. right ventricle

Question 2

Which physiological process is affected by Fallot’s tetralogy?

Answer 2

the sequential flow of deoxygenated blood through the right heart to the lungs and oxygenated blood through the left heart to the body

Question 3

What are the 4 structural defects associated with Fallot’s tetralogy?

Answer 3

1. ventricular septal defect
2. pulmonary stenosis
3. overriding aorta
4. right ventricular hypertrophy

Question 4

What is the VSD?

Answer 4

a hole in the heart

Question 5

What is pulmonary stenosis?

Answer 5

Narrowing of the pulmonary valve

Question 6

What is overriding aorta?

Answer 6

The position of the aorta is over the right ventricle as well as the left

Question 7

What is right ventricular hypertrophy?

Answer 7

The wall of the right ventricle becomes more muscular due to high pressure

Question 8

Why do patients with Fallot’s tetralogy have low oxygenation of blood?

Answer 8

This is due to the mixing of oxygenated and deoxygenated blood in the left ventricle via the VSD

Question 9

What is the right-to-left shunt in Fallot’s tetralogy patients?

Answer 9

Preferential flow of the mixed blood from both ventricles through the aorta

Due to the obstruction to flow through the pulmonary valve

Question 10

What causes Fallot’s tetralogy?

Answer 10

It is congenital but is believed to be caused by both genetic and environmental factors

Question 11

What is the primary symptom of Fallot’s tetralogy?

Answer 11

Low blood oxygen saturation with or without cyanosis

Question 12

What is cyanosis?

Answer 12

Blue appearance due to low level of oxygen in arterial blood

Question 13

What are other symptoms of Fallot’s tetralogy?

Answer 13

1. difficulty feeding
2. failure to gain weight
3. retarded growth and physical development
4. dyspnoea on exertion

Question 14

What clinical signs are visible in patients with Fallot’s tetralogy?

Answer 14

1. heart murmur
2. clubbing of fingers and toes
3. polycythaemia
4. “tet spells”

Question 15

What does the heart murmur sound like?

Answer 15

It can range from almost imperceptible to very loud

Question 16

What is polycythaemia?

Answer 16

Large amount of red blood cells

Question 17

What happens during a “Tet spell”?

Answer 17

Sudden, marked increase in cyanosis followed by syncope

May result in hypoxic brain injury and death

Question 18

How do older children react to a “Tet spell” and why?

Answer 18

They squat

This increases systemic vascular resistance and allows for a temporary reversal of the shunt

Question 19

What will an echocardiogram of a patient with Fallot’s tetralogy show?

Answer 19

The abnormal anatomy

The Eisenmenger complex

Question 20

What is the Eisenmenger complex?

Answer 20

A shunt of blood initially passes from left to right

Later on it will begin to shunt from right to left

Question 21

What will an X-ray look like of a patient with Fallot’s tetralogy?

Answer 21

Abnormal “coeur-en-sabot” appearance (boot-like) of the heart

Question 22

What treatment is given for “Tet spells”?

Why?

Answer 22

Oxygen

It is a potent pulmonary vasodilator and systemic vasoconstrictor

This allows more blood flow to the lungs

Question 23

What surgical procedure is performed for early management of a baby with Fallot’s tetralogy?

Answer 23

Forming an anastomosis (join) between the subclavian artery and pulmonary artery

This allows more blood to get to the lungs

Question 24

What is the purpose of curative heart surgery in patients with Fallot’s tetralogy?

Answer 24

It is designed to relieve the right ventricular outflow tract stenosis by removal of muscle and repair of the VSD

Question 25

Despite surgery, what do patients remain at increased risk of?

Answer 25

sudden cardiac death and heart failure