Congenital Heart Disease Flashcards
What is the most common class of congenital defects?
-cardiac
What is the most common type of cardiac defect?
septal defects, specifically VSD (42%) followed by ASD (10%)
What is the most common cyanotic congenital heart defect?
-tetralogy of Fallot
What genetic conditions are associated with heart defects?
-Down syndrome (tri 21)
-Marfan syndrome (FBN1)
-DiGeorge sydrome (22q11)
- Turner syndrome (XO)
- Patau syndrome (tri 13)
- Edward syndrome (tri 18)
What is the most genetic cause of cardiac defects?
Down syndrome
What cardiac defects are associated with Down syndrome?
- endocardial cushion defects -> atrioventricular
- VSD
- ASD
What cardiac defects are associated with Marfan syndrome?
- aortic aneurysm/dissection
- mitral/aortic valve prolapse
decreased elasticity -> failure of high pressure structures (ie. aorta/left-sided valves)
What cardiac defects are associated with DiGeorge syndrome?
-tetrology of Fallot
-conotruncal defects
-VSD
-ASD
What cardiac defects are associated with Turner syndrome?
- coarctation of the aorta
- bicuspid arotic valve
What are the different structural congenital abnormalities of the heart?
Left-to-right shunt (acyanotic):
- atrial septal defect (ASD)
- ventricular septal defect (VSD)
- patent ductus arteriosis (PDA)
- patent foramen ovale (PFO)
Right-to-left shunt (cyanotic):
- tetralogy of Fallot (TOF)
- transposition of the great arteries (TGA)
- tricuspid atresia
Obstructive:
- coarctation of the aorta
- pulmonary stenosis/atresia
- aortic stenosis/atresia
What feature clinical features generally differentiates between L-to-R and R-to-L shunts?
L-to-R:
- typically asymptomatic initially, may progress to become symptomatic later
- not cyanotic at birth
R-to-L:
- cyanosis
- nail clubbing
- hypertrophic osteoarthropathy
What is ASD?
defect in the septum between the atria of the heart
-allows high pressure blood from the LA to flow into the RA -> left-to-right shunt
What are the types of atrial septal defects?
Primum ASD:
- defect in lower septum, near AV valves
- typically associated with AV valve anomalies or VSD
- 5% of ASD
Secundum ASD:
- defect in center of atrial septum
- 90% of ASD
Sinus venosa defects:
- defect in septum near superior vena cava
- 5% of ASD
What are clinical features of ASD?
Typcially asymptomatic until >30
- systolic ejection murmur of pulmonary valve (increased right sided blood flow)
- pulmonary HTN (reversible)
What are complications of ASD?
- pulmonary HTN (typically reversible)
- paradoxyical embolism
- heart failure
- Eisenmenger syndrome if pulmonary HTN irreversible (rare)
What is the prognosis and treatment of ASD?
prognosis is normally very good (comperable to normal)
treatment is endovascular repair which prevents complications and normally revereses pulmonary HTN
What is PFO?
patent foramen ovale
- transient opening in the septum of the atria that is open during fetal development allowing blood to bypass the lungs
- foramen ovale permanently closes in 80% of the population by 2 y/o
- 20% remain open and allow for a right-to-left shunt with an increase in right atrial pressure, as in pulmonary HTN
What is a complication of PFO?
paradoxical embolism
What is a VSD?
defect in the septum between the ventricles of the heart
-allows high pressure blood from the LV to flow into the RV -> left-to-right shunt
Where do most VSDs occur?
in the membranous portion of the ventricular septum (90%)
What are clinical features of VSD?
dependent of size of defect and pressence of other defects
most will have a holosystolic murmur (blood passing through defect during systole)
Small defects:
- can be asymptomatic and 50% close spontaneously
- usually isolated VSD
Large defects:
- frequently associated with tetralogy of Fallot -> additional abnormalities -> present during childhood
- pulmonary HTN and RVH -> eventual Eisenmenger syndrome
What are complications of VSD?
- irreversible pulmonary HTN -> Eisenmenger syndrome -> death
- paradoxyical embolism
- heart failure
- arrhythmia (interuption of bundle branches?)
What is the prognosis and treatment of VSD?
Prognosis is variable with size and pressence of other abnormalities
Small defects:
- may resolve spontaneously
- typically asymptomatic in childhood, can become symptomatic in adulthood
- can be corrected surgically but normally delayed to see if spontaneous resolution occurs
Symptomatic/large defects:
- corrected surgically without waiting
- lethal if untreated through progression to Eisenmenger syndrome
What is Eisenmenger syndrome?
caused by L-to-R shunts:
- shunt causes increased pulmonary flow
- > pulmonary HTN
- > pulmonary remodeling and RVH-> increased pulmonary resistance (irreversible)
- > RV pressure exceeds LV pressure -> reversal of shunt (R-to-L now)
- > venous blood diverted from lung and reenters systemic circulation -> cyanosis
What is PDA?
patent ductus arteriosus:
- transient connection between in the pulmonary artery and aorta that is open during fetal development allowing blood to bypass the lungs
- ductus arteriosis normally involutes in first 2 days of life to form the ligamentum arteriosum
involution may not occur or be delayed in newborns that are hypoxic or with other defects producing increased pulmonary pressure
What are clinical features of PDA?
-harsh, “machinery” murmur: continuous murmur
initially asymptomatic at birth, can become symptomatic if not corrected
What are complications of PDA?
- heart failure
- Eisenmenger syndrome
What is the prognosis and treatment of PDA?
Why might you want to keep the ductus arteriosis open and how?
can be left untreated if asymptomatic w/ no signs of complicaitons (pulmonary HTN or hypertrophy)
can be closed in infants with indomethacin
PDA w/ TGA/TOF:
- kept open to allow for R-to-L shunt as pulmonary and systemic circulations will be isolated otherwise
- kept open with PGE1
What is TOF?
(features)
Tetralogy of Fallot:
- VSD
- RVH
- pulmonary valve stenosis (**dictates degree of severity**)
- overriding aorta (aortic opening positioned above VSD)
combination results in a R-to-L shunt
What are clinical features of TOF?
Severity determined by degree of pulmonary stenosis
can intially be asymptomatic but is progressive
-cyanosis at birth
-holosystolic murmur (vaires with VSD)
-systolic ejection murmur (varies with pulmonary stenosis)
“Tet spells”:
- cyanosis and syncope during increased cardiac demand
- compensatroy squatting to improve symptoms
What radiologic finding can be seen with TOF?
RVH -> upturned cardiac apex = “boot-shaped” heart
What is the prognosis and treatment of TOF?
prognosis determined by degree of pulmonary stenosis
-progressive worsening is expected, eventually requiring surgical correction
- supportive treatement of Tet spells until surgery is required
- if severe at birth, PGE1 is given to keep ductus arteriosus open followed by surgery
What is TGA?
transposition of the great arteries:
- aorta and pulmonary artery are switched
- aorta connected to RV
- pulmonary artery connected to LV
**results in isolation of the pulmonary and systemic circulations unless a shunt is present/made**
What are clinical features of TGA?
-cyanosis at birth
What is the prognosis and treatment of TGA?
prognosis determined by pressence/absence of shunting defect
What is tricuspid atresia?
atretic tricuspid valve accompanied by ASD/PFO, VSD, and right ventricular hypoplasia -> R-to-L shunt
left ventricle pumps blood fro both pulmonary and systemic circulation (functional univentricular heart)
What are clinical features of tricuspid atresia?
- severe cyanoisis at birth
- rough holosystolic murmur (through VSD)
What is the prognosis and treatment of TGA?
prognosis is very poor without treatment -> 75% die early in childhood
severity depends on pressence of VSD and patency of ductus venosus
Surgery to treat
What is coarctation of the aorta?
focal narrowing of the aorta at attachment of ductus arteriosus/ligamentum arteriosum (can be present with either)
- frequently associated with bicuspid aortic valve (50%)
- sometimes seen with septal defects and increased risk of berry aneurysm (dangerous due to increased cerbral BP)
What is the epidemiology of coarctation of the aorta?
more common in males
if female, high suspicion for Turner syndrome (XO)
What are the types
What the different types of coarctation of the aorta and what their clinical features?
both forms present with high systemic pressure in the head, neck and upper extremities (supplied by vessels proximal to narrowing) and low systemic pressure in lower trunk and lower extremities (supplied by vessels distal to the narrowing) -> pulse anomalies
Infantile:
- presents at birth
- narrowing proximal to a PDA
- deoxygenated blood flows into low pressure aorta distal to narrowing -> systemic blood of trunk and lower extremities is less oxygenated and low pressure (more severe)
- cyanosis of the lower half of body (differential cyanosis)
Adult:
- typically asymptomatic and presents later in life
- narrowing across form ligamentum arteriosum (no PDA)
- systemic blood of trunk and lower extremities is oxygenated but still perfuses at lower pressure
- claudication/cool lower extremities
What radiologic finding can be seen with coarctation of the aorta?
What causes it?
rib notching
- takes time to develop, >5 y/o
- caused by collaterals formed between internal thoracic arteries (proximal) and intercostal arteries (distal)
- the pulsation of enlarged intercostal arteries causes notching in the ribs
What is the prognosis and treatment of TGA?
prognosis depends primarily on degree of narrowing, additionally, location of narrowing can also matter with PDA
Treatment:
- PGE1 to keep perfusion until surgery in cases of severe coarctation proximally
- surgery to correct (resection, bypass or prosthesis)
- <5 can consider balloon angioplasty
What is hypoplastic left heart syndrome?
atretic aorta with hypoplastic left ventricle
- systemic circulation comes from ASD with PDA
- lethal if PDA closes
