Transcript Cyanotic Heart Lesions

Cyanotic Heart Lesions
Neonatal Intensive Care Nursery
Night Curriculum Series
Cyanosis
• Arterial saturation less than 90% and a PO2 less than
60 torr
• In all cyanotic heart lesions the amount of cyanosis
seen is dependent on the amount of pulm blood
flow
o Decreased PBF- increased cyanosis
o Increased PBF- minimal cyanosis but CHF may develop
• With 100% oxygen
o PO2 >250 is not congenital heart disease
o PO2 <100 is cardiac disease
5 “T’s”
• Most common cyanotic lesions of the newborn
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o
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Tetralogy of Fallot
Transposition of the Great Arteries
Truncus Arteriosus
Total Anomalous Venous Return
Tricuspid Atresia
General Sources of Arterial
Saturation
Decreased Pulmonary
Blood Flow
Admixture Lesions
Increased Pulmonary
Blood Flow
Tetralogy of Fallot
Transposition of Great
Vessels
Truncious Arteriosus
Tricuspid Atresia
Anomalous pulmonary
venous return
Pulmonary Atresia
PGE
• For cyanotic heart lesions with reduced blood flow
• RE-opens PDA and prevents it from closing
• Allows partially desaturated systemic arterial blood
to enter the pulmonary artery and be oxygenated
• Initial dose 0.1mg/kg/min
• Side effects- apnea, fever, hypotension
Complete Transposition
of the Great Arteries
• 5% of all CHD
• Boys 3:1
• Most common cyanotic condition that requires
hospitalization in the first two weeks of life
Complete Transposition of
the Great Arteries
• Aorta arises from the right ventricle
• Pulmonary artery arises from the left ventricle
Complete Transposition of
the Great Arteries
• Complete
separation of the
2 circuits
o Hypoxemic blood
circulating in the
body
o Hyperoxemic
blood circulating
in the pulmonary
circuit
Complete Transposition of
the Great Arteries
• Defect to permit
mixing of 2
circulations- ASD, VSD,
PDA.
o VSD is present in 40% of cases
• Necessary for survival
Clinical Symptoms
• Depend on anatomy present
• No mixing lesion and restrictive PFO
o
o
o
o
o
Profound hypoxia
Rapid deterioration
Death in first hours of life
Absent respiratory symptoms or limited to tachypnea
Single second heart sound, no murmurs
Clinical Symptoms
• Mixing lesion present (VSD or large PDA)
o
o
o
o
Large vigorous infant
Cyanotic
Little to no resp distress
Most likely to develop CHF in first 3-4 months of life
• excessive sweating (a cold, clammy sweat often noted during
feeding); poor feeding, slow weight gain, irritability or lethargy,
and/or rapid breathing
CXR
• Egg shaped
cardiac silhouette
• Narrow superior
mediastinum
Management
• Prostaglandin to establish
patency of the ductus
arteriosus
o Increases shunting from
aorta into the pulmonary
artery
o Increases pulmonary
venous return distending
the left atrium
o Facilitates shunting from
the left to the right atrium
of fully saturated blood
across the foramen ovale.
Management
• Therapeutic balloon atrial septostomy (Rashkind
Procedure) if surgery is not going to be performed
immediately
• Improves mixing and pulmonary venous return at
the atrial level
Treatment
• Surgery consists of switching the right and left sided
structures at the atrial level, at the ventricular level,
or at the great artery level.
Tetraology of Fallot
1.
2.
3.
4.
VSD
RVOT Obstruction
RVH
Overriding aorta
Two Important
Abnormalities
• NonRestrictive VSD
o Large enough to equalize pressures in both ventricles
• Degree of RVOT
Clinical Presentation of
Cyanotic TOF
• Cyanosis, clubbing, dyspnea on exertion, squatting,
hypoxic spells.
• Loud systolic ejection murmur, systolic thrill at
middle LSB
• Soft murmurs are associated with less blood flow
and more hypoxia
CXR- boot shaped
Hypoxic Spell
(“TET Spell”)
• Peak incidence of 2-4 months
• Characterized by:
o
o
o
o
Hyperapnea (Rapid and deep respirations)
Irritability and prolonged crying
Inc cyanosis
Decreased heart murmur
Pathophysiology
o Lower SVR or inc
resistance of RVOT
can increase the RL shunt
• Stimulates the
respiratory center to
produce
hyperapnea
• Results in an
increase in systemic
venous return
• In turn, increases R-L
shunt through VSD
TET Spell Treatment
1. Hold infant in knee-chest position
2. Morphine
3. Sodium bicarbonate to treat acidosis- decreases
resp stimulating effect of acidosis
4. Vasoconstrictor (phenylephrine)
5. Propranolol
Treatment
• Early surgical repair depending on pt’s weight
• VSD is closed and obstructing ventricular muscle is
removed
Total Anomalous Pulmonary
Venous Return
• The pulmonary veins drain into the RA or its venous
tributaries rather than the LA
• A interatrial communication (ASD or PFO) is
necessary for survival
• Pulmonary venous return reaches the RA
o Systemic and pulmonary venous blood are completely mixed
4 Types
1. Supracardiac
Common pulmonary vein drains into the SVC via the
left SVC and left innominate vein.
2. Cardiac
• The common PV drains into the coronary sinus
3. Infracardiac
• The common PV drains into the portal vein, ductous
venosus, hepatic vein, or IVC.
Infracardiac-type TAPVC. Pulmonary
venous blood draining through the liver to
reach the IVC and right atrium.
4. Mixed
• A combination of the other types
Clinical Signs for
Unobstructed Veins
• Mild cyanosis, signs of CHF in infancy, history of
pneumonia
• Widely split S2, Grade 2-3/6 systolic murmur heard
at the ULSB
• CXR- marked cardiomegaly
Clinical Signs for
Obstructed Veins
• Profound desaturation
• Acidosis
• PGE1 administration does not improve oxygenation
because elevated pulmonary pressures in the right
side of the heart (due to obstructed pulmonary
outflow) will result in right to left shunting across an
open ductus further decreasing arterial saturation.
Treatment
• Digitalis and diuretics to treat heart failure
• Intubation and inc PEEP for those with severe pulm
over load
• Corrective surgery
Tricuspid Atresia
• Tricuspid valve is absent
• RV and PA are hypoplastic
• Associated defects- ASD, VSD, or PDA (necessary
for survival)
• Dilation of LA and LV
• Essentially single
ventricle physiology
Clinical Signs
• Severe cyanosis, poor feeding, tachypnea
• Single S2, grade 3/6 systolic murmur at LLSB if VSD is
present
• CXR- boot shaped heart
Treatment
• PGE IV infusion
• Blalock-Taussig shunt in infancy
o systemic to pulmonary arterial shunt
o Provide stable blood flow to the lungs
o A gortex tube is sewen between the subclavian artery and the right
pulmonary artery
Bidirectional Glenn
• Superior vena cava is connected to the pulmonary
arteries
• IVC continues to be connected to the heart
Fontan Procedure
• Redirects IVC to lungs
Truncus Arteriosus
• A single trunk leaves the heart
o Gives rise to pulm, systemic, and coronary
circulations
o Large VSD is always present
Clinical Signs
• Cyanosis immediately after birth
• Early signs of CHF
• 2-4/6 systolic murmur at LSB suggestive of VSD
Treatment
• Anticongestive medications (diuretics and digitalis)
• Corrective surgery
o VSD is closed
o Pulmonary artery is separated from the truncus
o Continuity is then established between the right ventricle and the
pulmonary artery utilizing a valved homograft conduit