1. Congenital Heart Defects
Chapter 30
Congenital Heart Defects

2. Cardiac Defects Patent Ductus Arteriosus Atrial Septal Defect
Ventricular Septal Defect
Tetralogy of Fallot
Transposition of the Great Arteries
Coarctation of the Aorta
Anomalous Venous Return
Truncus Arteriosus
Hypoplastic Left-Heart Syndrome

3. Heart Congenital heart disease (CHD) occurs in 1/125 live births.
Neonates may present with a variety of non-specific findings, including:
- tachypnea
- cyanosis
- pallor
- lethargy
- FTT
- sweating with feeds
More specific findings include:
- pathological murmurs hypertension
- abnormal pulses syncope

4. Neonatal cardiac physiology
The transformation from fetal to neonatal circulation involves two major changes:
A marked increase in systemic resistance.
caused by loss of the low-resistance placenta.
2. A marked decrease in pulmonary resistance.
caused by pulmonary artery dilation with the neonate’s first breaths.

5. Fetal Circulation No circulation to lungs Foramen ovale
Ductus arteriosum
Circulation must go to placenta
Umbilical aa., vv.

7. Fetal cardiac physiology
Fetal circulation:
Blood flows from the placenta
 IVC
 RA
 through the PFO
 LA
 LV
 ascending aorta
 brain
 returns via the SVC

8. Fetal cardiac physiology
Fetal circulation:
From the SVC
 RA
 RV
 pulm aa
 through the PDA
 descending aorta
 lower extremities and placenta

9. Fetal cardiac physiology
Fetal circulation:
Only a very small amount of blood is directed through the right and left pulmonary aa’s to the lungs.

10. Neonatal cardiac physiology
Neonate circulation:
The transformation to neonatal circulation occurs with the first few breaths.
The two remaining remnants of the fetal circulation are a patent foramen ovale...
and ductus arteriosus.

11. Congenital Heart Disease
Neonates with CHD often rely on a patent ductus arteriosus and/or foramen ovale to sustain life.
Unfortunately for these neonates, both of these passages begins to close following birth.
The ductus normally closes by 72hrs.
The foramen ovale normally closes by 3 months.

12. CHD
That being said, in the presence of hypoxia or acidosis (generally present in ductus-dependent lesions), the ductus may remain open for a longer period of time.
As a result, these patients often present to the ED during the first 1-3 weeks of life.
i.e. as the ductus begins to close.

13. Classifying CHD
There are many different classification systems for CHD.
None are particularly good.
I will be discussing the Pink/Blue/Grey-Baby system:
Pink Baby – Left to right shunt
Blue Baby – Right to left shunt
Grey Baby – LV outflow tract obstruction

14. Pink Baby (L  R shunt)
L  R shunts cause CHF and pulmonary hypertension.
This leads to RV enlargement, RV failure, and cor pulmonale.
These babies present with CHF and respiratory distress.
They are not typically cyanotic.

15. Pink Baby (L  R shunt)
These lesions include (among others) ASD’s, VSD’s, and persistently patent ductus arteriosus.
VSD
ASD

16. Persistently patent ductus arteriosus
Pink Baby (L  R shunt)
Persistently patent ductus arteriosus

17. Pink Baby (L  R shunt) Diagnosing L  R shunts depends on:
1. Examination findings:
Non-cyanotic infant in resp distress.
Crackles, widely-fixed second heart sound, elevated JVP, cor pulmonale.
2. CXR:
Increased pulmonary vasculature (suggestive of CHF).
RA and/or RV enlargement.

18. Pink Baby (L  R shunt)
Initial management should be directed at reducing the pulm edema.
Adminster Lasix 1mg/kg IV.
Peds Cardiology/ PICU should be consulted urgently regarding use of:
Morphine
Nitrates
Digoxin
Inotropes

19. Ductus Arteriosus Fetal Circulation Component Closure secondary to:
Connects Pulmonary Artery to Aorta
Shunts blood away from lungs
Maintained patent by presence of prostaglandins
Closure secondary to:
Increase in PaO2_
Decrease in level of prostaglandins

20. Patent Ductus Arteriosus
5-10% of all births (1 of 2000 live births)
80% of premature babies
2-3 times more common in females than males.
5th or 6th most common congenital cardiac defect.
Often associated with other defects.
May be desirable with some defects.
Morbidity/Mortality related to degree of blood flow through PDA.

22. Pathophysiology - PDA
With a drop in pulmonary arterial pressure (reduction in hypoxic pulmonary vascular constriction), blood will flow through PDA.
LEFT TO RIGHT SHUNT
Increased pulmonary blood flow may lead to pulmonary edema.
Reduced blood flow to all postductal organs
NEC
If pulmonary artery pressure rises above Aortic pressure, blood will move in the other direction.
RIGHT TO LEFT SHUNT

23. Diagnosis - PDA
Loud grade I to grade III systolic murmur at left sternal border.
Washing machine
Echocardiography

24. Treatment - PDA Restrict fluids. Diuretics
Prostaglandin Inhibitors - Indomethacin
Surgical closure (ligation).

25. Atrial Septal Defect 6-10% of all births (1 of 1500 live births)
2 times more common in females than males.
Types:
Ostium Secundum (at or about the Foramen Ovale)
Sinus Venous
In 1950 most children with ASD did not reach the first grade. Today, first year surgery facilitates normal growth and development.

29. ASD: Pathophysiology and Diagnosis
Left to Right Shunt
Inefficient recirculation of good blood through pulmonary arteries.
May not manifest symptoms and may be found later in life.
If defect is significant, may cause problems later in life due to inefficiencies.
Diagnosis
Murmur
Echocardiography

30. Treatment - ASD Surgical closure.
Non-Surgical closure via cardiac catheterization.

31. Ventricular Septal Defect
1% of all births (2 to 4 of 1000 live births)
Vast majority the hole is small.
In 1950, fatal. Today almost all VSD can be closed successfully, even in small babies. Lillehei was the first person in history to correct both ASD and VSD on 8/31/54.

34. VSD: Pathophysiology & Diagnosis
May be isolated or associated with other congenital cardiac defects.
With normal PVR:
LEFT TO RIGHT SHUNT
With elevated PVR (RDS):
RIGHT TO LEFT SHUNT
Diagnosis
Echocardiography

35. Treatment - VSD Nothing if VSD is small.
With CHF or Failure to Thrive: Surgical closure.

36. Blue Baby (R  L shunt)
R  L shunts cause hypoxia and central cyanosis.
Neither hypoxia or cyanosis tend to improve with 100% oxygen.
R  L lesions include (among others):
Tetralogy of Fallot (TOF)
Transposition of the Great Arteries (TGA)

37. Blue Baby (R  L shunt)
Hypoxia and cyanosis (unresponsive to oxygen) in the neonatal period suggests a ductus-dependent lesion.
Treatment is a prostaglandin-E1 (PGE1) infusion.
Dosing discussed momentarily
This should obviously be accompanied by urgent Peds Cardiology and PICU consultation.

38. Tetralogy of Fallot * * * *
Characterized by:
Pulmonary aa OTO
RV hypertrophy
VSD
Over-riding aorta
With severe pulmonary OTO... * * *
bloodflow to the lungs may be highly ductus-dependent. *

39. Tetralogy of Fallot Pulmonary vasculature is typically decreased.
The classic CXR finding in TOF is the boot-shaped heart.
Pulmonary vasculature is typically decreased.

40. Tetralogy of Fallot 1% of neonates.
Most common of the cyanotic cardiac diseases.
Mortality increases with age (1 year-old has a 25% mortality, 40 year-old has 95%).
In 1950, fatal. Today, less than 5% mortality with children operated on in infancy, leading normal lives. Four Defects
Pulmonary Artery Stenosis (determinant factor related to severity)
VSD (usually large)
Overriding Aorta
RV hypertrophy

43. Tetralogy of Fallot: Diagnosis and Treatment
Tet Spells (Blue spells)
CXR: Boot-shaped Heart
Diagnosed with echocardiography.
Surgical correction.
Reparative or Palliative (Blalock-Taussig)

45. Blalock-Taussig
Something the Lord Made.
Vivien Thomas

46. Tetralogy of Fallot

47. Transposition of the Great Arteries
TGA is one of the most common cyanotic lesion presenting in the first week of life.
Anatomically:
RV  aorta
LV  pulmonary aa
To be compatible with life, mixing of the two circulations must occur via an ASD, VSD, or PDA.

48. Transposition of the Great Arteries
The CXR findings in TGA are typically less dramatic than in TOF.
Pulmonary vasculature is typically increased.

49. Complete Transposition of the Great Arteries
Second most common form (5-7%) of congenital cardiac anomalies.
Aorta arises from RV and Pulmonary Arteries from LV.
Without an abnormality, life would not be possible.
ASD
VSD (30-40%)
PDA

52. Transposition – Diagnosis and Treatment
Chest X-Ray: “Egg on a String”
Echocardiography
Cardiac Catheterization (?)
Treatment
Balloon septostomy during cardiac cath.
Rashkind’s Procedure
Reestablish Foramen Ovale
Prostaglandin E1 to keep PDA open.
Surgical Correction
Jantene Operation

54. Grey Baby (LVOTO) X
Left-ventricular outflow tract obstructions (LVOTO’s) lead to cyanosis, acidosis, and shock early in the neonatal period.
Complete obstruction is universally fatal unless shunting occurs through an ASD, VSD, or PDA.
Examples of these lesions include:
Severe coarctation of the aorta
Hypoplastic left heart syndrome (HLHS)

55. Grey Baby (LVOTO) Treatment:
Any neonate presenting with shock unresponsive to fluids +/- pressors has a LVOTO until proven otherwise.
As with the Blue babies, appropriate management is an urgent PGE1 infusion and emergent consultation.

56. Coarctation of the Aorta
7% of congenital cardiac defects.
Constriction of the aorta.
Results in severely reduced blood flow.
Increased work on the heart leading to CHF and cardiovascular collapse.
Location of narrowing determines the clinical signs.
Usually associated with PDA, VSD and a defective aortic valve.

58. Location of Coarctation
Pre-Ductal
Less common but more serious
Associated with VSD, PDA, Transposition
Post-Ductal
More common
Often associated with collateral circulation beyond coarctation, which minimizes effect.
Diagnosed by a difference in blood pressure between lower extremities and upper ones.
Pressure in upper extremities > lower

59. Coarctation – Diagnosis and Treatment
Chest X-Ray
Echocardiography
Cardiac catheterization
Treatment
Support with inotropic agents (Dopamine).
Prostaglandins to maintain PDA.
Surgical repair

61. Anomalous Venous Return
Return of pulmonary venous blood to the right atrium instead of the left.
ASD is present to sustain life.
Can also be partial.
Cyanosis usually present.
Diagnosed with echocardiography.
Surgical correction with reimplantation of pulmonary veins.

63. Truncus Arteriosus
Defect in which one large vessel arises from right and left heart over a large VSD.
Cyanosis is often present.
CHF common.
Diagnosed with echocardiography and cardiac catheterization.
Surgery:
Separate pulmonary arteries from truncus.
Closure of VSD
Create valved connection between RV and Pulmonary Artery

65. Repair of Truncus Arteriosus

66. Hypoplastic Left-Heart Syndrome
Several anomalies:
Coarctation of the aorta
Hypoplastic left ventricle
Aortic and mitral valve stenosis or atresia.
Cyanotic defect.
Right heart pumps blood to body through PDA.
Closure of PDA results in hypotension, shock, and death.
Maintain hypoxemia with normalized CO2 levels.
“40-40 Club”

67. 2 Coarctation of the aorta 3 Patent ductus arteriosus 4 Narrowed aorta
1 Patent foramen ovale
2 Coarctation of the aorta
3 Patent ductus arteriosus
4 Narrowed aorta
5 Hypoplastic left ventricle
6 Aortic atresia
                                                                                     

68. Surgical Treatment of Hypoplastic Left Heart Syndrome
Three separate surgeries.
Norwood procedure
First few days after birth.
Glenn Shunt (Cavo Pulmonary Connection)
3-9 months of age
Fontan Procedure
2 years of age
Less wait because of damage from pulmonary hypertension.

69. Stage I - Norwood Procedure

70. Stage II - Glenn Shunt

71. Stage III – Fontan Procedure

72. Prostaglandin-E1 PGE1 promotes ductus arteriosus patency.
Use an IV infusion at ug/kg/min.
A response should be seen within 15 min.
If ineffective, try doubling the dose.
If effective, try halving the dose.
The lowest possible dose should be used– as adverse-effects of PGE1 can include:
- fever
- flushing
- diarrhea
- periodic apnea (be ready to intubate)

73. Remnants of Fetal Circulation
Ligamentum teres = Round ligament
Remnant of the umbilical vein
Anterior abdominal wall
Ligamentum venosum
Remnant of ductus venosum
On liver’s inferior surface
Medial Umbilical Ligaments
Remnant of umbilical arteries
Anterior abdominal wall below navel
Also gives branch to urinary bladder

74. Clinical Monitoring Blood pressure Oxygen saturation
End tidal carbon dioxide

75. Respiratory Care of Patients with Cardiac Anomalies
Vascular resistance
Ventilator management
Inhaled nitric oxide
Subambient oxygen
Hypercarbia