Congenital Heart Defects Flashcards
What are maternal risk factors for congenital heart disease in children?
- Age >40
- Poorly controlled diabetes during pregnancy
- Congenital infection during pregnancy such as rubella
- Aspirin intake
- Systemic lupus
- Phenytoin intake
What is left to right-sided heart failure?
In a left-to-right shunt, oxygenated blood from the left side of the heart mixes with the right side of the heart. The SaO2 on the left side of the heart is 95% and normally on the right side, it is 75%. As the blood mixes, the SaO2 on the right side of the heart is increased to 80% or more.
What is the consequence of left to right-sided HF?
Volume overload will occur in the right side of the heart. This leads to pulmonary hypertension, right and left ventricular hypertrophy, and later a reversal of the shunt because the right side of the heart will end up with higher pressures than the left and the shunt reverses. This is known as Eisenmenger syndrome. This is considered late-onset cyanosis and will result in clubbing of the fingers
What is ventricular septal defect?
This results in a hole in the interventricular septum. This allows blood to move from the left ventricle to the right ventricle.
What are the characteristics of VSD?
The infant/child will have a hard holosystolic murmur at the lower, left sternal border. Infants with a large VSD can develop heart failure and have poor weight gain. Adults will develop pulmonary HTN, cyanosis, and clubbing.
What is an arterial septal defect?
Most common in adults. The most common cause is a patent foramen ovale that does not close. This allows blood to flow from the left atrium to the right atrium.
What are the characteristics of ASD?
ASD is associated with fetal alcohol syndrome and Down syndrome. They will have a crescendo-decrescendo systolic murmur. They are at an increased risk of developing an embolus.
What is patent ductus arteriosus?
PDA results from the ductus arterisus not closing after birth. This duct should normally close a few weeks after birth.
What are the characteristics of PDA?
A machine-like murmur is heard continuously through systole and diastole. The blood moves from the aorta to the pulmonary arteries. This increases blood in the pulmonary artery, thus increasing pulmonary blood flow, which in turn increases the amount of blood returned to the left side of the heart. A reversal of the shunt can occur where deoxygenated blood will enter the aorta causing the child to be cyanotic in the lower portion of their body but normal in the upper body.
What occurs in right to left-sided heart shunts?
Deoxygenated blood is mixed with oxygenated blood. The SaO2 on the left side of the heart drops from 95% to 80% or lower. A SaO2 <80% will result in cyanosis.
What is the most common right-to-left-sided heart shunt?
Tetralogy of Fallot
