Transposition Of The Great Arteries

Question 1

What is transposition of the great arteries (TGA)?

Answer 1

It is defined as a condition in which the attachments of the aorta and the pulmonary trunk to the heart are transposed

Question 2

What class of congential heart disease is transposition of the great arteries?

Answer 2

Cyanotic

Question 3

What is the pathophysiological cause of transposition of the great arteries?

Answer 3

It is due to failure of the aorticopulmonary septum to spiral during septation

Question 4

What is the pathophysiology of transposition of the great arteries?

Answer 4

The right ventricle pumps blood into the aorta, and the left ventricle pumps blood into the pulmonary vessels

Therefore, there are two separate circulations that don’t mix: one travelling through the systemic circulation and right side of the heart and the other travelling through the pulmonary system and left side of the heart

Question 5

What is the pathophysiological consequence of transposition of the great arteries?

Answer 5

In order to enable immediate survival, there is shunt development between the systemic circulation and the pulmonary circulation, which enables blood flowing through the body to become oxygenated within the lungs

This shunt can occur across a patent ductus arteriosus, atrial septal defect or ventricular septal defect

Question 6

What four risk factors are associated with transposition of the great arteries?

Answer 6

Diabetic Mother

Gestational Smoking

Gestational Alcohol Consumption

Rubella Infection

Question 7

What are the seven clincial features of transposition of the great arteries?

Answer 7

Failure To Thrive

Difficulty Feeding

Diaphoresis

Cyanosis

Systolic Murmur

Right Ventricular Thrill

Tachypnoea

Question 8

What is diaphoresis?

Answer 8

It is defined as excessive sweating

Question 9

Describe the murmur associated with transposition of the great arteries

Answer 9

There is a loud single S2

It is loudest at the left sternal border

Question 10

In most cases, how is transposition of the great arteries diagnosed?

Answer 10

Antenatal Ultrasound Scans

Question 11

What should be conducted following antenatal diagnosis of transposition of the great arteries?

Answer 11

There should be close montioring and secondary care arrangements made in order to ensure urgent management

Question 12

What two investigations are used to diagnose transposition of the great arteries?

Answer 12

Chest X-Ray (CXR)

ECHO Scans

Question 13

What is the feature of transposition of the great arteries on CXRs?

Answer 13

‘Egg On A String’ Appearance

Question 14

What is the gold standard investigation used to diagnose transposition of the great arteries?

Answer 14

ECHO Scans

Question 15

What are the three features of the transposition of the great arteries on ECHO scans?

Answer 15

Parallel Great Vessels With An Absence of Crossing

Pulmonary Artery Branched From Left Ventricle

Aorta Branched From Right Ventricle

Question 16

What is the pharmacological management option of transposition of the great arteries?

Answer 16

Prostaglandin E1 Infusion

Question 17

When is prostaglandin E1 infusion used to manage transposition of the great arteries?

Answer 17

It is the first line management option

Question 18

How is prostaglandin E1 infusion used to manage transposition of the great arteries?

Answer 18

It is used to maintain the ductus arteriosus, in order to enable blood from the aorta to flow to the pulmonary arteries for oxygenation

Question 19

Name a prostaglandin E1 analogue used to manage transposition of the great arteries

Answer 19

Alprostadil

Question 20

What are the two surgical management options of transposition of the great arteries?

Answer 20

Balloon Septostomy

Open Heart Surgery

Question 21

What is balloon septostomy?

Answer 21

It involves insertion of a catheter into the foramen ovale via the umbilicus, and inflating a balloon to create a large atrial septal defect

This enables blood returning from the lungs to flow to the right side of the heart and out through the aorta to the body

Question 22

What is the definitive management option of transposition of the great arteries?

Answer 22

Open Heart Surgery

Question 23

What open heart surgery is used to manage transposition of the great arteries?

Answer 23

It involves the use of a cardiopulmonary bypass machine to perform an arterial switch procedure

In addition, when there is presence of an atrial septal defect or ventricular septal defect, it can be corrected at the same time