Congenital Heart Disease

Question 1

What is the most common class of congenital defects?

Answer 1

-cardiac

Question 2

What is the most common type of cardiac defect?

Answer 2

septal defects, specifically VSD (42%) followed by ASD (10%)

Question 3

What is the most common cyanotic congenital heart defect?

Answer 3

-tetralogy of Fallot

Question 4

What genetic conditions are associated with heart defects?

Answer 4

-Down syndrome (tri 21)

-Marfan syndrome (FBN1)

-DiGeorge sydrome (22q11)

• Turner syndrome (XO)
• Patau syndrome (tri 13)
• Edward syndrome (tri 18)

Question 5

What is the most genetic cause of cardiac defects?

Answer 5

Down syndrome

Question 6

What cardiac defects are associated with Down syndrome?

Answer 6

• endocardial cushion defects -> atrioventricular
• VSD
• ASD

Question 7

What cardiac defects are associated with Marfan syndrome?

Answer 7

• aortic aneurysm/dissection
• mitral/aortic valve prolapse

decreased elasticity -> failure of high pressure structures (ie. aorta/left-sided valves)

Question 8

What cardiac defects are associated with DiGeorge syndrome?

Answer 8

-tetrology of Fallot

-conotruncal defects

-VSD​

-ASD

Question 9

What cardiac defects are associated with Turner syndrome?

Answer 9

• coarctation of the aorta
• bicuspid arotic valve

Question 10

What are the different structural congenital abnormalities of the heart?

Answer 10

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

Question 11

What feature clinical features generally differentiates between L-to-R and R-to-L shunts?

Answer 11

L-to-R:

• typically asymptomatic initially, may progress to become symptomatic later
• not cyanotic at birth

R-to-L:

• cyanosis
• nail clubbing
• hypertrophic osteoarthropathy

Question 12

What is ASD?

Answer 12

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

Question 13

What are the types of atrial septal defects?

Answer 13

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

Question 14

What are clinical features of ASD?

Answer 14

Typcially asymptomatic until >30

• systolic ejection murmur of pulmonary valve (increased right sided blood flow)
• pulmonary HTN (reversible)

Question 15

What are complications of ASD?

Answer 15

• pulmonary HTN (typically reversible)
• paradoxyical embolism
• heart failure
• Eisenmenger syndrome if pulmonary HTN irreversible (rare)

Question 16

What is the prognosis and treatment of ASD?

Answer 16

prognosis is normally very good (comperable to normal)

treatment is endovascular repair which prevents complications and normally revereses pulmonary HTN

Question 17

What is PFO?

Answer 17

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

Question 18

What is a complication of PFO?

Answer 18

paradoxical embolism

Question 19

What is a VSD?

Answer 19

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

Question 20

Where do most VSDs occur?

Answer 20

in the membranous portion of the ventricular septum (90%)

Question 21

What are clinical features of VSD?

Answer 21

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

Question 22

What are complications of VSD?

Answer 22

• irreversible pulmonary HTN -> Eisenmenger syndrome -> death
• paradoxyical embolism
• heart failure
• arrhythmia (interuption of bundle branches?)

Question 23

What is the prognosis and treatment of VSD?

Answer 23

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

Question 24

What is Eisenmenger syndrome?

Answer 24

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

Question 25

What is PDA?

Answer 25

_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**

Question 26

What are clinical features of PDA?

Answer 26

-harsh, **"machinery" murmur:** _continuous murmur_ **initially asymptomatic** at birth, can become **symptomatic if not corrected**

Question 27

What are complications of PDA?

Answer 27

- heart failure - Eisenmenger syndrome

Question 28

What is the prognosis and treatment of PDA? Why might you want to keep the ductus arteriosis open and how?

Answer 28

**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**

Question 29

What is TOF? | (features)

Answer 29

_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

Question 30

What are clinical features of TOF?

Answer 30

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**

Question 31

What radiologic finding can be seen with TOF?

Answer 31

RVH -\> upturned cardiac apex = **"boot-shaped" heart**

Question 32

What is the prognosis and treatment of TOF?

Answer 32

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**

Question 33

What is TGA?

Answer 33

_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\*\*

Question 34

What are clinical features of TGA?

Answer 34

-cyanosis at birth

Question 35

What is the prognosis and treatment of TGA?

Answer 35

prognosis determined by pressence/absence of shunting defect

Question 36

What is tricuspid atresia?

Answer 36

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)

Question 37

What are clinical features of tricuspid atresia?

Answer 37

- severe cyanoisis at birth - rough holosystolic murmur (through VSD)

Question 38

What is the prognosis and treatment of TGA?

Answer 38

**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

Question 39

What is coarctation of the aorta?

Answer 39

**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)

Question 40

What is the epidemiology of coarctation of the aorta?

Answer 40

more common in **males** **if female**, high suspicion for **Turner syndrome** (XO)

Question 41

What are the types

Question 42

What the different types of coarctation of the aorta and what their clinical features?

Answer 42

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**

Question 43

What radiologic finding can be seen with coarctation of the aorta? What causes it?

Answer 43

**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

Question 44

What is the prognosis and treatment of TGA?

Answer 44

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**

Question 46

What is hypoplastic left heart syndrome?

Answer 46

**atretic aorta** with **hypoplastic left ventricle** - systemic circulation comes from **ASD with PDA** - lethal if PDA closes