34. Congenital heart disease with left to right shunt. Flashcards
what is a left to right shunt ?
oxygenated blood (from left side) enters into the part of circulation where usually only deoxygenated blood flows (right side of circulation) → thus, deoxygenated blood simply becomes more oxygenated → therefore no cyanosis.
left-to-right shunt the volume- & pressure overload is the major problem
what is a major complication of left to right shunt?
↑ BF to the lungs → thickening in pulmonary vessels → narrowing of lumen → ↑ pulmonary pressure!
At some point pressure in the right site of circulation becomes higher than the pressure on the left side and the shunts reverses to a right-to-left shunt (cyanotic) → The reversion of BF direction through a shunt is knowns as ‘EISENMENGER SYNDROME’
what are the different types of left to right shunts ?
ASD
VSD
PDA
what are the clinical features of atrial septal defect ?
asymptomatic up to 30 years
frequent respiratory infections in children
failure to thrive
complaints associates with pulmonary hypertension
right heart failure
what are the physical findings in those individuals with atrial septal defect ?
Widely fixed split OF s2 over the second left ICS,- pulmonary zone
systolic ejection murmur in pulmonary auscultary zone-some pulmonary valve stenosis
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Low-pitched mid diastolic murmur in tricuspid auscultatory zone - due to increased flow though the tricuspid valve
Right-ventricular S3 gallop
what are the three subtypes in atrial septal defect ?
ostium primum atrial septal defect (seen in trisomy 21);
accompanied by other heart defects
earlier development of pulmonary hypertension and cardiomegaly
Mitral regurgitation often present
supraventricular arrhythmias
Often AV-block
2.ostium secundum atrial septal defect;
usually isolated
Typically a low-pressure, low-volume,
minor left-to-right shunt (therefore, patients are asymptomatic)
3.sinus-venosus-defect
what are the diagnostic findings in atrial septal defect ?
ECHO - dilated right atria and ventricle
paradoxical septal movemnet in hemodynamically significant
doppler view
or we can use contrast echo - to see the contrast bubles being shunted left to right
Trasn esophageal echo - we can see a direct visualisation
ecg - in ostium secindum - we see right axis deviation
with incomlete or complete rbbb
in ostium primum - we see left axis deviation
with complete or incomlete RBBB
RV hypertrophy - p pulmonale , pr prolong , incomplete RBBB
chest x ray - we see dilated pulmonary arteries
cardiomegaly
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cardiac catheterisation :
oxohemometry
manometry
what are associated with atrial septal defect secundum ?
5-10% in combination with pulmonary stenosis
- 10% combination of anomalous inflow of pulmonary veins (mainly in sinus venosus type)
- 2-8% in combination with mitral stenosis
treatment for ASD?
in children - spontaneous closure
Hemodynamically insignificant defect – Conservative
Hemodynamically significant defect
Interventional methods
Use of CardioSEAL, Amplatzer (including closure of patent foramen ovale, a common sourse of paradoxical embolism which is the cause of strokes in young people).
– Surgical closure
Eisenmenger’s syndrome – heart lung transplant
what causes ASD ?
Down syndrome
Fetal alcohol syndrome
Holt-Oram syndrome (hand-heart syndrome)
Autosomal dominant disorder
Characterized by ASD, a first-degree heart block, and abnormalities of the upper limbs (e.g.,
what are the complication of all types of atrial septal defects ?
Paradoxical embolism
venous thromboembolus passes through a shunt from the inferior vena cava entering into the arterial circulation
and stroke and infraction
cause of VSD?
Down syndrome, Edward syndrome, Patau syndrome
Intrauterine infections (e.g., TORCH) Maternal risk factors: diabetes
CAN OCCUR WITH TETRALOGY OF FALLT
or TGA
what are the different classification of VSD?
- muscular septum (largest);
- posterior septum (comprises endocardial cushion tissue);
- supracristal septum (compromises conotruncal tissue);
- membranous septum (smallest)
most commonly- membranous
clinical features of VSD?
Small defects: usually asymptomatic
Medium-sized or large defects
Lead to heart failure by the age of 2–3 months
what are the physical findings of ventricular septal defect ?
auscultation
HARSH holosystolic murmurs -
heard best in the left 3rd (erbs point) and 4 th intercostal space (tricuspid area)
radial propagation
Becomes more intense with maneuvers that increase left ventricular afterload (e.g., handgrip)
Typically louder in small defects
pathologicaly split S2
Loud pulmonic S2 if pulmonary hypertension develops
Mid-diastolic murmur over cardiac apex - due to increased flow of mitral valve
systolic thrills
how do you diagnose VSD?
echocardiograph with doppler
ecg
medium sized or large
Signs of RV hypertrophy (due to pulmonary hypertension or obstruction of the pulmonary outflow tract): vertical or right axis deviation,
P pulmonale,
PR prolongation,
complete or incomplete right bundle branch block
Signs of LV hypertrophy (due to volume loading)
↑ QRS amplitude, left axis deviation, p mitrale
cardiac catheterisation
oxohemometry
Manometry
elevated pressure in the right ventricle
and higher oxygen saturation
treatment of VSD
Small defects often heal spontaneously
symptomatic and large defects :
surgical repair
in children less than 1 yr indicating pulmonary hypertension
in older children
Special modifications of dual- sided occluders – CardioSEAL, STARFlex and Amplatzer
what are the causes for patent ductus arteriosus ?
Prematurity
Maternal exposure during pregnancy: Rubella Alcohol Phenytoin Prostaglandin use Trisomies (e.g., Down syndrome)
what are the clinical features with patent ductus arteriosus ?
small
large - failure to thrive
heart failure symptoms
physical findings for patent ductus arteriosus ?
Heaving, laterally displaced apical impulse = left v overload
Bounding peripheral pulses, wide pulse pressure
Machinery murmur: loud continuous murmur
2-3 left parasternal intercostal space
propagation towards left subclavian space , left axilla
and best heard in left infraclavicular region
and loudest at S2
what is the diagnosis of PDA?
echo and doppler
can show blood flow from the aorta into the pulmonary artery.
ECG
left axis deviation
cardiac catheterisation and angiography
ANGIOGRAPHY
in right catheterisation -passes through pulmonary artery to aorta - typical shape of TREBLE CLEF
direct visualisation if injected with contrast dye = only necessary in prior repair
what is the treatment for PDA?
treat the heart failure
= pharmacological closure in premature infants with infusion of indomethacin and ibuprofen
in infants percutaneous catheter occlusion less than 2.5mm occlusion with special wire coil - gianturco coils or surgical ligation
large ducts
diameter more tha 2.5mm
amplatzer or cardioseal system
when do we administer prostaglandin to keep the PDA open ?
for survival such as TGA and tetralogy of fallot
hypo plastic left heart
complication of PDA?
infective endocarditis
