Suspecting Congenital Heart Disease in Newborns

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Suspecting Congenital Heart Disease in Newborns

• To ECHO or not to ECHO,
• that is the question

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Goal and Objective

• Feel comfortable with a newborn cardiac exam
• Know when to worry
• Know what to do if you are worried

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When to worry

• The happy blue baby
• Harsh murmurs
• Unexplained hypoxia or tackypnea
• Poor feeding and weight gain
• Chromosomal abnormality associated with CHD
• Family history of CHD

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Risk Factor Familial History

• Incidence of CHD increases by three to fourfold
  when a first order relative has CHD
• Risk increases by 10 fold if two first-order
  relatives have CHD

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Risk Factor Maternal Disease

• Infants of Diabetic Mothers
• Five times greater risk of cardiac anomalies than
  general population
• myocardial hypertrophy, vsd double outlet rv,
  transposition of the great vessels, truncus
  arteriosus, and coarctation of aorta
• Maternal Lupus congenital heart block
• Rubella PDA, PS, VSD, ASD

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Risk Factor Mode of Delivery

• Vaginal delivery and good Apgar scores most
  common with CHD
• Cesarean section and Poor Apgar scores more
  indicative of asphyxia and respiratory distress

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TAGA male, SVD, apgars 8,8
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Have a higher index for suspicion with certain
diagnoses

• Infants of diabetic mothers are 3 times more
  likely to have congenital heart defects VSD,
  ASD, TGA
• DiGeorge syndrome conotruncal defects,
  coarctation, interrupted arch, tetralogy
• Downs syndrome 50 incidence
• Trisomy 18 90 incidence
• Turners syndrome 40 incidence

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Prevalence of CHD

• Up to 1 in every 100 births
• 25 VSD
• 5-10 ASD, PDA, Coactation, Tetralogy, Pulmonary
  valve stenosis, Aortic valve stenosis,
  transposition
• 1-5 Hypoplastic left or right, Truncus, TAPVR,
  Tricuspid atresia, DORV

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Normal newborn cardiac physiology

• DA closes physiologically and anatomically,
  physiologically in 2 to 3 days and anatomically
  in 1 to 3 weeks. Frequently hear a murmur as the
  duct closes.
• All babies are born with pulmonary hypertension
  and RVH, right sided pressures drop rapidly after
  birth in response to increase PaO2 and distending
  pressure in the airways
• Murmurs arise from shunting blood across the
  ductus or the PFO

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Red Flags for Heart Disease

• Immediate findings
• Cyanosis not explained by lung disease, the happy
  blue baby
• Apgars of 8,8
• Harsh murmur
• Tachypnea
• Abnormal heart sounds, prominent or single S2
• Later findings
• Poor feeding
• Slow weight gain
• Enlarged liver
• Rapid decompensation at 1 to 3 weeks of life

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Clinical Presentation Central Cyanosis

• Cyanosis in the first week of life may be the
  sole evidence of CHD
• Results from desaturated blood leaving the heart
• A bluish discoloration of tongue and mucous
  membranes reflecting arterial desaturation
• Present in both Cardiac and Respiratory disease

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Peripheral Cyanosis

• Results from sluggish movement of blood through
  the extremities and increased tissue oxygen
  extraction
• Persists from birth
• Can last several days
• Does NOT involve mucous membranes
• NOT a result of CHD

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Clinical Presentation

• Newborns with severe CHD usually have one or more
  of the following
• Central Cyanosis
• Respiratory Distress
• CHF
• Abnormal Cardiac Rhythm
• Cardiac Murmur

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Clinical Presentation Respiratory Pattern

• Tachypnea without dyspnea
• Breathing fast yet easy
• Crying may worsen cyanosis in infants with CHD
  because crying increases oxygen consumption by
  tissues and doesnt increase blood flow to lungs
  if defect causes blood to by-pass the lungs

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Clinical Presentation Respiratory Pattern

• Significant respiratory distress most consistent
  with pulmonary cause of cyanosis

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Clinical PresentationHeart Sounds

• S1 First heart sound
• Closure of the mitral and tricuspid valves
• S2 Second heart sound
• Closure of aortic and pulmonic valves
• Split S2 is normal occurance reflecting closure
  of aortic valve before the pulmonic valve

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Murmurs

• Murmurs are audible vibrations resulting from
  turbulence of blood flow and may be due to
• abnormal valves
• septal defects
• regurgitated flow through incompetent valves
• high blood flow across normal structures

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Murmurs

• Physiologic murmurs have been noted in 50 of
  neonates in the first 48 hours of life
• left to right flow via PDA
• Increase flow over pulmonary valve associated
  with fall in PVR

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Evaluation of Murmurs

• Intensity of sound (grades I-VI)
• Timing within cardiac cycle (systolic/Diastolic)
• Quality and pitch

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Murmurs

• Absence of a murmur does not rule out heart
  disease

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Blood Pressure

• Normal values are dependent on birth weight and
  gestational age
• Term
• Systolic range 55-90
• Mean diastolic 30-55
• Preterm MAP gestational age and 5mmhg
• Compare upper and lower extremity
  pressures.Systolic 20 above the LE indicative of
  arch anomalies

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Chest X-ray examination

• Rule-out pulmonary parenchymal disease
• Evaluate pulmonary blood flow
• increased versus decreased blood flow

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Chest X-ray Examination

• Cardiac Size
• Cardio-thoracic ratio greater than 65 consistent
  with cardiomegaly

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Cardiac Position Dextrocardia

• Situs inversus Situs solitus

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Congestive Heart Failure

• A set of clinical signs and symptoms that reflect
  the hearts inability to deliver adequate oxygen
  to meet the metabolic requirements of the body

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Definitions

• Tetrology of Fallot right ventricular outflow
  tract stenosis, VSD, over-riding aorta and RVH.
  Pink versus blue tet depends on the amount RV
  outflow stenosis.
• Truncus arteriosus a common vessel is the
  outflow of both the left and right ventricle
• TAPVR absence of any connection between
  pulmonary return and the left atrium. There are
  variations in drainage, but blood generally
  returns to the right atrium.

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• the aorta and pulmonary artery start as a single
  blood vessel, which eventually divides and
  becomes two separate arteries. Truncus arteriosus
  occurs when the single great vessel fails to
  separate completely, leaving a connection between
  the aorta and pulmonary artery.

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• ventricular septal defect, that allows blood to
  pass from the right ventricle to the left
  ventricle without going through the lungs
• a narrowing (stenosis) at or just beneath the
  pulmonary valve that partially blocks the flow of
  blood from the right side of the heart to the
  lungs
• the right ventricle is more muscular than normal
  (RVH)
• the aorta lies directly over the ventricular
  septal defect (over-riding aorta)

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So you suspect CHD, what to do now?
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Is the lesion cyanotic or acyanotic?

• Perform a hyperoxyic challenge
• Place infant in 100 oxygen and repeat blood gas.
  If you can get the PaO2 gt150 a cardiac shunt is
  very unlikely and pulmonary disease is more
  likely your culprit. A rise in PaO2 of less than
  20 is concerning for cyanotic heart disease.
  (some use PaO2 of 100 as break point)

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Is pulmonary blood flow increased or decreased?

• CXR

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Other Diagnostic Tests

• Arterial Blood gas values
• Helpful in determining lung versus cardiac causes
  of cyanosis
• PaCO2 NL with cardiac disease
• elevated with lung disease

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Acyanotic lesions with increased pulmonary blood
flow

• These lesions will have left to right shunting
• ASD, VSD AV canals and PDA
• All have communication between the systemic and
  pulmonary circulation which causes fully
  oxygenated blood to be shunted back into the
  lungs
• These infants will do well initially. They will
  eventually develop CHF. They generally do not
  need emergent treatment or transport, just close
  follow up.

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• there is an abnormal opening between the two
  upper chambers of the heart - the right and left
  atria causing an abnormal blood flow through
  the heart. Some children may have no symptoms and
  appear healthy. However, if the ASD is large,
  permitting a large amount of blood to pass
  through the right side, symptoms will be noted.

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• in this condition, a hole in the ventricular
  septum occurs. Because of this opening, blood
  from the left ventricle flows back into the right
  ventricle, due to higher pressure in the left
  ventricle. This causes an extra volume of blood
  to be pumped into the lungs by the right
  ventricle, which can create congestion in the
  lungs.

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• Prior to birth, there is an open passageway
  between the aorta and pulmonary artery, which
  closes soon after birth. When it does not close,
  some blood returns to the lungs. Patent ductus
  arteriosus is often seen in premature infants.

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Enlarged heart with increased vascular markings
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Acyanotic lesions with decreased or normal
pulmonary blood flow

• These lesions generally have obstruction to
  normal blood flow
• Valvular pulmonic or aortic stenosis, coarctation
  or the aorta.
• Their presentation depends on the amount of
  obstruction. Infants with severe obstruction
  will become critically ill within hours. Infants
  will mild obstruction may not present for months
  to years.

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• in this condition, the aortic valve between the
  left ventricle and the aorta did not form
  properly and is narrowed, making it difficult for
  the heart to pump blood to the body. A normal
  valve has three leaflets or cusps, but a stenotic
  valve may have only one cusp (unicuspid) or two
  cusps (bicuspid). Although aortic stenosis may
  not cause symptoms, it may worsen over time, and
  surgery may be needed to correct the blockage -
  or the valve may need to be replaced with an
  artificial one.

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• the aorta is narrowed or constricted, obstructing
  blood flow to the lower part of the body and
  increasing blood pressure above the constriction.
  Usually there are no symptoms at birth, but they
  can develop as early as the first week after
  birth. If severe symptoms of high blood pressure
  and congestive heart failure develop, and surgery
  may be considered.

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Cyanotic lesions with decreased pulmonary blood
flow

• These lesions have both obstruction to flow and
  right to left shunting.
• Tricuspid atresia, tetrology, single ventricle
  with pulmonary stenosis.
• Early pulmonary flow can be maintained through
  the DA, when that closes infants will quickly
  decompensate.
• Most of these infants will need early
  intervention and transport.

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• in this condition, there is no tricuspid valve,
  therefore, no blood flows from the right atrium
  to the right ventricle. Tricuspid atresia defect
  includes the following
• a small right ventricle
• a large left ventricle
• diminished pulmonary circulation
• cyanosis - bluish color of the skin and mucous
  membranes caused from a lack of oxygen.
• A surgical shunting procedure is often necessary
  to increase the blood flow to the lungs.

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Cyanotic lesions with increased pulmonary blood
flow

• No obstruction to blood flow. Cyanosis is from
  abnormal AV connections or total mixing within
  the heart.
• TGA, TAPVR, truncus arteriosus
• These babies may not appear in distress but will
  generally need early intervention and transport.

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• with this congenital heart defect, the positions
  of the pulmonary artery and the aorta are
  reversedthe aorta originates from the right
  ventricle, so most of the blood returning to the
  heart from the body is pumped back out without
  first going to the lungs.the pulmonary artery
  originates from the left ventricle, so that most
  of the blood returning from the lungs goes back
  to the lungs again

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• In TAPVR, the four pulmonary veins are connected
  somewhere besides the left atrium. There are
  several possible places where the pulmonary veins
  can connect. The most common connection is to a
  blood vessel that brings oxygen-poor (blue) blood
  back to the right atrium, usually the superior
  vena cava.

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Immediate treatment of cyanotic heart disease

• Use oxygen with caution, in lesions with
  increased pulmonary flow, too much oxygen can be
  a bad thing. Most infant will do fine with
  saturations of 75 to 85
• Treat metabolic acidosis
• Start prostoglandins to prevent closure of the
  DA, this can be life saving in lesions with
  ductral dependent flow. (Hypoplastic left,
  coarctation, tetrology, atresias)

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Prostaglandin E1 (Alprostadil)

• Vasodilator which acts on the smooth muscle of
  the ductus arteriosus
• Start at 0.05 mcg/kg/min and titrate down to the
  lowest effective rate
• Side effects include seizures, hypocalcemia,
  apnea, hypotension, hyperthermia and
  thrombocytopenia
• Best given through a central venous line

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References

• www.lpch.org/DiseaseHealthInfo/HealthLibrary/cardi
  ac/ta.html
• (Lucille Packard Hospital)