Flashcards in CHAPTER 8: CARDIAC PATHOLOGY Deck (42):
When do most congenital heart defects arise?
During weeks 3-8 (critical period) of embryogenesis
What is a Ventral Septal Defect (VSD)?
Defect in the interventricular septum that results in left-to-right shunting of blood
What is the most common congenital heart defect?
What teratogen are VSDs associated with?
Fetal Alcohol Syndrome (FAS)
Describe how a VSD could lead to Eisenmenger Syndrome.
First, know that Eisenmenger Syndrome refers to the reversal of shunting such that there is RIGHT-TO-LEFT shunting of blood
1) VSD= Left-to-right shunt (LV high pressure-->low pressure RV)
2) Increased blood volume in the RV leads to pulmonary artery HTN and RVH
3) RV pressure eventually becomes greater than LV pressure
Thus, there is RIGHT-TO-LEFT shunting causing cyanosis.
What is the treatment for a VSD?
- If small, typically spontaneously closes
- Large= surgical closure
What is an Atrial Septal Defect (ASD)?
Defect is the atrial septum leading to left-to-right atrial shunting
What is the most common type of ASD?
What syndrome is an ostium primum associated with?
What is the clinical manifestation of an ASD?
Split S2 (fixed)
Why do ASDs cause splitting of S2?
1) Blood is shunted from LA to RA
2) Increased RA volume= increased RV volume
3) Increased RV volume= longer ejection time and delayed closure of the pulmonary valve compared to aortic
Thus, S2--the heart sound associated with the closure of the semilunar valves--is split.
What is an important complication of an ASD?
*This is when an embolus e.g. a DVT enters the RA and passes through the defect into the LA; it is then ejected into the system circulation where it can lodge in the brain or extremities.
What is the normal function of the Ductus Ateriosus?
- Connection between the fetal pulmonary artery and aorta
- Allows oxygenated blood from the mother to bypass the immature fetal lungs
What is a Patent Ductus Arteriosus (PDA)?
Failure of the ductus arteriosus to close
What is PDA associated with?
What type of shunting does a PDA result in?
Describe the murmur associated with a PDA.
What is the treatment for PDA?
*Decreases PGE, which results in closure of the PDA
Explain why a PDA can lead to LE cyanosis later in life it not corrected.
1) Ductus ateriosus connects PA to Aorta AFTER the three major branches that go to the head and UE
2) Left-to-right shunting results in pulmonary HTN
3) Reversal of shunt will cause "blue blood" to go into systemic circulation AFTER the three major branches
What are the four characteristics of Tetralogy of Fallot (TOF)?
1) Stenosis of the pulmonary outflow tract
3) Over-riding aorta
What type of shunting is seen in TOF?
Right-to-left leading to early cyanosis
What determine the degree of cyanosis in TOF?
Degree of stenosis
What do patients with TOF do in response to a TET spell? Why do they do this?
Squat--increased arterial resistance decreases shunting and allows more blood to reach the lungs
What is the classic finding associated with TOF on CXR?
What is Transposition of the Great Vessels (TGA)?
This is when the pulmonary artery arises from the LV, and aorta arising from the RV
What is TGA associated with?
How does TGA present?
What is required for an infant with TGA to survive?
Shunting; thus, PGE is given to keep a PDA open prior to surgical correction
What is Truncus Arteriosus?
This is when a single large vessel arises from both ventricles
How does a patient with Truncus Arteriosus present?
What is Tricuspid Atresia?
This is when the tricuspid valve orifice fails to develop AND the RV is hypoplastic
What is Tricuspid Atresia commonly associated with?
How does Tricuspid Atresia present?
What is Coarctation of the Aorta?
Narrowing of the aorta
What are the two types of Coarctation of the Aorta?
Infantile and adult
What is infantile Coarctation of the Aorta associated with?
Where is the coarctation seen in the infantile form of Coarctation of the Aorta?
- Coarctation lies DISTAL to the arch but PROXIMAL to the PDA
- Present with LE cyanosis
What genetic defect is Coarctation of the Aorta associated with?
What is adult Coarctation of the Aorta?
Coarctation lies DISTAL to the aortic arch, but NO PDA
How does adult Coarctation of the Aorta present?
Hypertension in the UE but hypotension in the LE
What is Coarctation of the Aorta associated with in adults?
Bicuspid aortic valve