| What are Acyanotic Defects | Acyanotic defects of the neonatal heart are anatomical anomalies that DO NOT usually interfere with the oxygenation of the blood |
| What are the differences between a fetal heart and a newborn heart? | The foramen ovale is open in a fetal heart but closed in a newborn heart, same for the ductus arteriosus which is also closed after birth |
| What is a common acynotic defect | Basically failure of the closure of the opening in the septal wall post natally
Since left atrial pressure is higher than right , the blood flow would be from left to right so there is no mixing of deoxygenated blood with the systemic circulation hence is a acynotic defect
Most common site is the foramen ovale |
| When does the ductus arteriosus close and how does it close? | Ducuts arteriosus closes after birth because of the drop in pulmonary pressure following perfusion of the lungs ( it constricts ) |
| What is Patent Ductus Arteriosus | Failure to close the ductus arteriosus
left to right shunting of blood does not cause cyanosis but can be problematic later if not treated
Chronic left to right shunting can lead to vascular remodelling in the pulmonary circulation and lead to increase in resistance which can put more strain on the right side of the heart |
| What are examples of cyanotic defects | Bascially any defect that affects oxygenation of the blood leading to cyanosis
Tetralogy of Fallot
Tricuspid atresia
Transposition
Pericardial Effusion
Hypoplastic left heart syndrome |
| In Tetralogy of Fallot, what are the four abnormalities | Ventricular septal defect → there is a hole between the two chambers of the heart known as the ventricles
Overriding aorta
Pulmonary stenosis
Right ventricular hypertrophy
So basically this leads to increase in pressure in the right side of the heart so there is right to left shunting due to the septal defect so there is mixing of deoxygenated blood with oxygenated blood leading to a cyanotic defect |
| What is Transposition of great arteries | Results in two unconnected parallel circulations instead of two circulations in series
In this defect the right ventricle is connected to the aorta and the left ventricle to the pulmonary trunk
This condition is not compatible with life after birth unless a shunt exists to allow the two circulations to communicate |
| What is Hypoplastic Left Heart Syndrome | Left ventricle significantly decreased in size
Can be due to Mitral stenosis
Leads to a small aorta
Heart’s ability to pump oxygenated blood around the body is impaired |
| What is the general things done during surgery for Hypoplastic Left Heart Syndrome | First week of life, aorta is reconstructed and eventually overgrows it
Basically after 4-6 months, the SVC is disconnected from the heart and connected directly to the pulmonary artery and the original stunt is removed
And then after 18-36 months, the IVC is disconnected and then connected directly to pulmonary artery so basically the body bypasses the heart for oxygenation |
