Congenital Heart Disease

Question 1

Heart Folding

Answer 1

Right (d-looping) causes the atrium and sinus venosus to migrate cranially; neural crest cells by this point have participated in Aorticopulmonary septation and helped form the primitive aortic arches

(Roughly week 4)

Question 2

What forms the borders of the AVC?

Answer 2

Cardiac jelly, fusion of superior and inferior endocardial cushions

=»Endocardial cells then differentiate to form the fibrous portion of the valves

Question 3

3 origins of the membranous part of the IVS

Answer 3

Right bulbar ridge, left bulbar ridge, and the av septum (endocardial cushions)

Question 4

By what day does the heart have 4 chambers

Answer 4

50

Question 5

1st aortic arch =»

Answer 5

Maxillary and external carotid arteries

Question 6

Third aortic arch =»

Answer 6

Common carotid artery

Question 7

Fourth aortic arch =»

Answer 7

Left= aortic arch; right=subclavian

Question 8

Sixth aortic arch =»

Answer 8

Right= RPA/LPA; Left= Ductus arteriosus

Question 9

Pulmonary Vein development

Answer 9

Lung buds from the embryonic foregut incorporate a common vein to the left atrium at week 8 and separate into two distinct veins by week 12

Question 10

What does the sinus venosus become?

Answer 10

The smooth part of the RA

Question 11

Atrial Septal Defect

Answer 11

Leads to right atrial enlargement, right ventricular enlargement, and increased pulmonary flow

Clinical: Soft systolic ejection mumur at the left upper sternal border, fixed split S2, and prominent RV impulse

CXR may show cardiomegaly; echo is gold standard

Tx: May close spontaneously or can close w/ cardiac catheterization procedure

Question 12

Ventricular Septal Defect

Answer 12

Most common congenital heart disease

Blood flows from LV to RV causing increased pulmonary flow, some LV enlargement, and LA enlargement

Signs:Presents at ***4-8 weeks w/ tachypnea, diaphoresis, failure to thrive

PE: Hyperdynamic precordium, holosystolic mumur at lower left sternum, possible mid-diastolic rumble at the apex w/ large defects

Tx: Surgery

Question 13

PDA

Answer 13

Common in preemies; decreased pulmonary resistance at birth causes L=>R shunting increasing return and leading to LA and LVL enlargement

Signs: Tachypnea, diaphoresis

PE: Harsh, machine-like murmur at the upper left sternal border, tachypnea

PDA: Indomethacin, cardiac catheterization procedure

Question 14

Atrioventricular Septal Defect

Answer 14

Partial defect is similar to ASD, complete defect has combination of ASD and VSD (severe)

Clinical: Partial =» asymptomatic; Complete =» CHF signs

PE: Partial- Fixed S2 impulse, systolic ejection murmur at upper left sternal border
Complete-Loud S2, hyperdynamic precordium, murmur at lower-left sternum

Tx: Partial- Observation, elective surgery when older
Complete- Management of CHF, surgery at 3-6months

Question 15

Aortic coarction

Answer 15

Commonly seen in Turner’s Syndrome (XO); causes a rise in EDV leading to increased LV and LA pressures and pulmonary edema

***HTN in upper extremities; hypotension in lower extremities

PE: CHF signs once ductus arteriosus closes; possibly mild HTN in older children

Tx: PGE1 to maintain ductus arteriosus, inotropy support, correction of metabolic acidosis

Question 16

Hypoplastic Left Heart Syndrome

Answer 16

Self-described; causes a dominant right heart and causes things light aortic atresia/stenosis alongside mitral atresia/stenosis depending on the size of the LV

-While Ductus arteriosus is open, some blood from the pulmonary artery will enter systemic circulation

PE: Shock once PDA closes but mild cyanosis before that; usually seen prenatally

-Dyspnea, single loud S2

Tx: PGE1, inotropy help, hypoventilation to manage pulmonary resistance
-Eventual severe surgery is performed connecting the IVC to the pulmonary artery (FYI)

Question 17

Tetrology of Fallot

Answer 17

PROVe

-Initially a L=>R shunt due to V, hypertrophy of RV and increased pulmonary stenosis eventually changes it to R=>L shunt

PE: Normal S2, cyanosis, harsh systolic ejection murder on left sternal border that radiates to the back

*HYPERCYANOTIC EPISODES: acute increase in R=>L shunting that causes cyanosis, irritability, lethargy, hyperpnea
=»Put baby in knee-chest position to decrease VR and increase SVR (goal is to improve pulmonary flow)
-Also give IV fluids (increased pulmonary flow), morphine, phenylephrine, BB

***Boot-shaped heart on CXR

Tx: Surgery

Question 18

Tricuspid atresia

Answer 18

Pts. have interatrial communication, hypoplastic right ventricle, and a VSD
-Systemic venous return mixes w/ pulmonary return in LA, all pulmonary flow must go across the VSD and degree of cyanosis depends on this flow

PE: Neonatal (early) cyanosis, normal S2, left ventricular impulse

Tx: PGE1, surgery

Question 19

Transposition of the Great Vessels

Answer 19

Assoc. w/ patent foramen ovale, VSD, and aortic coarction; degree of mixing of blood determines cyanosis

PE: Neonatal cyanosis, may be a murmur

Tx: PGE1, surgery

Question 20

Truncus Arteriosis

Answer 20

Assoc. w/ 22q.11 deletion; pulmonary blood flow depends on resistance

PE: CHF, mild cyanosis, holosystolic murmur from VSD
***ONLY DISORDER TO HAVE A DIASTOLYLIC MURMUR TOO (from truncal regurgitation)

Question 21

Total Anomalous Pulmonary Venous Return

Answer 21

Assoc. w/ hetortaxy syndrome; Pulmonary arteries connect back to the RA; systemic flow depends on patent foramen ovale or ASD

PE: Unobstructed-Asymptomatic initially, then feeding problems, tachypnea, failure to thrive, widely split S2, systolic murmur
Obstructed- Severe respiratory distress and cyanosis on 1st day of life, normal cardiac signs

-Snowman sign on CXR, echo

Tx: Unobstructed- Medical therapy then surgery
Obstructed- SURGICAL EMERGENCY; stabilize (inotropics, PGE1, mecahnical ventilation) and surgery