34. Congenital heart disease with left to right shunt.

Question 1

what is a left to right shunt ?

Answer 1

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

Question 2

what is a major complication of left to right shunt?

Answer 2

↑ 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’

Question 3

what are the different types of left to right shunts ?

Answer 3

ASD
VSD
PDA

Question 4

what are the clinical features of atrial septal defect ?

Answer 4

asymptomatic up to 30 years

frequent respiratory infections in children

failure to thrive

complaints associates with pulmonary hypertension
right heart failure

Question 5

what are the physical findings in those individuals with atrial septal defect ?

Answer 5

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

Question 6

what are the three subtypes in atrial septal defect ?

Answer 6

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

Question 7

what are the diagnostic findings in atrial septal defect ?

Answer 7

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

Question 8

what are associated with atrial septal defect secundum ?

Answer 8

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

Question 9

treatment for ASD?

Answer 9

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

Question 10

what causes ASD ?

Answer 10

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.,

Question 11

what are the complication of all types of atrial septal defects ?

Answer 11

Paradoxical embolism
venous thromboembolus passes through a shunt from the inferior vena cava entering into the arterial circulation

and stroke and infraction

Question 12

cause of VSD?

Answer 12

Down syndrome, Edward syndrome, Patau syndrome

Intrauterine infections (e.g., TORCH)
Maternal risk factors: diabetes

CAN OCCUR WITH TETRALOGY OF FALLT

or TGA

Question 13

what are the different classification of VSD?

Answer 13

1. muscular septum (largest);
2. posterior septum (comprises endocardial cushion tissue);
3. supracristal septum (compromises conotruncal tissue);
4. membranous septum (smallest)

most commonly- membranous

Question 14

clinical features of VSD?

Answer 14

Small defects: usually asymptomatic

Medium-sized or large defects
Lead to heart failure by the age of 2–3 months

Question 15

what are the physical findings of ventricular septal defect ?

Answer 15

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

Question 16

how do you diagnose VSD?

Answer 16

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

Question 17

treatment of VSD

Answer 17

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

Question 18

what are the causes for patent ductus arteriosus ?

Answer 18

Prematurity

Maternal exposure during pregnancy:
Rubella 
Alcohol 
Phenytoin
Prostaglandin use
Trisomies (e.g., Down syndrome)

Question 19

what are the clinical features with patent ductus arteriosus ?

Answer 19

small

large - failure to thrive
heart failure symptoms

Question 20

physical findings for patent ductus arteriosus ?

Answer 20

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

Question 21

what is the diagnosis of PDA?

Answer 21

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

Question 22

what is the treatment for PDA?

Answer 22

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

Question 23

when do we administer prostaglandin to keep the PDA open ?

Answer 23

for survival such as TGA and tetralogy of fallot

hypo plastic left heart

Question 24

complication of PDA?

Answer 24

infective endocarditis