Transposition Of The Great Arteries Flashcards
What is transposition of the great arteries (TGA)?
It is defined as a condition in which the attachments of the aorta and the pulmonary trunk to the heart are transposed
What class of congential heart disease is transposition of the great arteries?
Cyanotic
What is the pathophysiological cause of transposition of the great arteries?
It is due to failure of the aorticopulmonary septum to spiral during septation
What is the pathophysiology of transposition of the great arteries?
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
What is the pathophysiological consequence of transposition of the great arteries?
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
What four risk factors are associated with transposition of the great arteries?
Diabetic Mother
Gestational Smoking
Gestational Alcohol Consumption
Rubella Infection
What are the seven clincial features of transposition of the great arteries?
Failure To Thrive
Difficulty Feeding
Diaphoresis
Cyanosis
Systolic Murmur
Right Ventricular Thrill
Tachypnoea
What is diaphoresis?
It is defined as excessive sweating
Describe the murmur associated with transposition of the great arteries
There is a loud single S2
It is loudest at the left sternal border
In most cases, how is transposition of the great arteries diagnosed?
Antenatal Ultrasound Scans
What should be conducted following antenatal diagnosis of transposition of the great arteries?
There should be close montioring and secondary care arrangements made in order to ensure urgent management
What two investigations are used to diagnose transposition of the great arteries?
Chest X-Ray (CXR)
ECHO Scans
What is the feature of transposition of the great arteries on CXRs?
‘Egg On A String’ Appearance
What is the gold standard investigation used to diagnose transposition of the great arteries?
ECHO Scans
What are the three features of the transposition of the great arteries on ECHO scans?
Parallel Great Vessels With An Absence of Crossing
Pulmonary Artery Branched From Left Ventricle
Aorta Branched From Right Ventricle
What is the pharmacological management option of transposition of the great arteries?
Prostaglandin E1 Infusion
When is prostaglandin E1 infusion used to manage transposition of the great arteries?
It is the first line management option
How is prostaglandin E1 infusion used to manage transposition of the great arteries?
It is used to maintain the ductus arteriosus, in order to enable blood from the aorta to flow to the pulmonary arteries for oxygenation
Name a prostaglandin E1 analogue used to manage transposition of the great arteries
Alprostadil
What are the two surgical management options of transposition of the great arteries?
Balloon Septostomy
Open Heart Surgery
What is balloon septostomy?
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
What is the definitive management option of transposition of the great arteries?
Open Heart Surgery
What open heart surgery is used to manage transposition of the great arteries?
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