March 1, 2016 - Obstructive Defects Flashcards
Fetal Shunts
Ductus venosus
Foramen ovale
Ductus arteriosus
Congenital Aortic Stenosis
When the ductus closes, infants with critical AS are often in severe CHF or cardiogenic shock.
Coarctation of the Aorta
A short segment narrowing of the aorta.
The blood pressure is higher before the coarctation than it is after. Can sometimes be detected by a difference in blood pressure in the arms and the legs.
Severe coarctation is often found in the first few weeks of life, however a less severe coarctation may go undiscovered for years.
Often have a bicuspid aortic valve.
Hypoplastic Left Heart Syndrome (HLHS)
The left ventricle is hypoplastic and poorly developed and there is an ASD. The mitral valve is also hypoplastic, and is poorly formed or not formed at all.
Bloodflow from both the lungs and the body flows into the right ventricle, and the right ventricle pumps blood to both the lungs and the body (through a patent ductus arteriosus [PDA]).
HLHS is referred to as a single ventricle defect.
If the PDA closes, the baby will become critically ill, and prostaglandin is needed to keep the PDA open until surgery can be performed during the first few weeks of life.
Total Anomalous Pulmonary Venous Return (TAPVR)
The pulmonary veins do not connect normally to the left atrium, but rather connect to the superior vena cava by an anomalous connecting vein. This results in oxygen-rich blood not going directly to the body.
An ASD is needed to move mixed blood into the left ventricle to deliver it to the body. Babies with TAPVR will need surgery within the first few weeks of life.
Pulmonary Atresia
The tricuspid valve does not develop.
Blood returning to the heart into the right atrium cannot travel into the right ventricle, it is instead shunted through the foramen ovale (or ASD) into the left atrium, ventricle, and back to the body.
The only way to get blood through the lungs are through the ductus arteriosum. Or, if there is a VSD, it can get back through to the pulmonary artery.
Without ventricular septal defects, is not compatible with life.
Ebstein Anomaly
A defect of the tricuspid valve.
The triscuspid valve is displaced inside the right ventricle, which causes regurgitation across the triscuspid valve into the right atrium.
There is typically a PFO or ASD which causes shunting across the atrium.
Tricuspid regurgitation and right ventricular hypertrophy can lead to heart failure.
