Congenital Defects Flashcards
(41 cards)
When do most congenital defects arise?
During embryogenesis (usually weeks 3-8)
What is the incidence and cause of congenital heart defects?
- Seen in 1% of live births
- Most defects are sporadic
What are the two different types of shunts that occur in congenital defects?
- Left to right - relatively asymptomatic at birth - but shunt can eventually reverse
- Right to left - presents as cyanosis shortly after birth
What is VSD (ventricular septal defect) associated with? What is it?
- Fetal alcohol syndrome
- Defect in the septum that divides the right and left ventricles
What is the most common heart defect?
Ventricular septal defect
What does VSD result in?
- Left-to-right shunt
- Size of defect determines extent of shunting and age at presentation
- Small defects are often asymptomatic
- Large defects can lead to eisenmenger syndrome
How does the VSD eventually cause cyanosis?
Inc. Pulmonary HTN –> reversal of shunt –> blue blood –> cyanosis
What is Eisenmenger syndrome?
RVH, polycythemia, clubbing (due to cyanosis)
What is an atrial septal defect (ASD)?
Defect in septum dividing right and left atria
-Results in Left to right shunt and split S2 on auscultation (increased blood in right heart delays closure of pulmonary valve)
What is the most common type of ASD?
Ostium secundum (90% of cases)
What is ostium premium type associated with?
Down Syndrome
What is an important complication of ASD?
Paradoxical emboli
-Can go through the shunt & you get emboli stroke rather than PE
What is a Patent Ductus Arteriosus (PDA)?
- Failure of ductus arteriosus to close
- Results in left-to-right shunt between aorta and the pulmonary artery
- -During development, the ductus arteriosus normally shunts blood from the pulmonary artery to the aorta, bypassing the lungs.
What maternal condition is PDA associated with?
Congenital Rubella
What symptoms are associated with PDA?
- Asymptomatic at birth with continuous “machine-like” murmur
- May lead to Eisenmenger syndrome, resulting in lower extremity cyanosis
What might you see on the lower extremities of PDA?
Lower extremity cyanosis
What do you use to treat PDA?
Indomethacin, which decreases PGE, resulting in PDA closure (PGE maintains patency of the ductus arteriosus)
What is Tetralogy of Fallot?
Characterized by (1) Stenosis of right ventricular outflow tract (2) Right ventricular hypertrophy (3) VSD (4) an aorta that overrides the VSD
What causes cyanosis in Tetralogy of Fallot?
Right to left shunt
-Degree of stenosis determines extent of shunting and cyanosis
What do you see on X-ray with Tetralogy of Fallot?
Boot-shaped heart
What do patients with Tetralogy of Fallot learn to do?
Squat in response to a cyanotic spell
-Increased arterial resistance decreases shunting and allows more blood to reach the lungs
What is transposition of the great vessels?
Characterized by pulmonary artery arising from the left ventricle and aorta arising from the right ventricle. (creates two continuous loops)
What does PGE do?
Keeps things open! Like PDAs
What maternal condition is Transposition of the great vessels associated with?
Maternal diabetes
