35. Congenital heart disease with right to left shunt.

Question 1

what are the common right to left shunts ?

Answer 1

Tetralogy of Fallot:- most common congenital heart disease

Transposition of the great arteries

Tricuspid atresia

Truncus arteriosus

Total anomalous pulmonary venous return

Question 2

etiology of Tetra of fallot?

Answer 2

sporadic

di george
down syndrome

maternal exposure
alcohol
phenylketonuria
diabetes

Question 3

what is the definition of tetra of fallot?

Answer 3

Right ventricular outflow tract obstruction (RVOTO) due to pulmonary infundibular stenosis

Right ventricular hypertrophy (RVH)

Ventricular septal defect (VSD)

Overriding aorta (above the VSD)

Question 4

what are the clinical findings on Teralogy of fallot?

Answer 4

cyanosis - depending on the left of pulmonary valve obstruction

Tet spells: intermittent hypercyanotic, hypoxic episodes with a peak incidence at 2–4 months after birth
associated with crying , feeding and defectation
caused by increased in pulmonary vascular resistance or decrease in systemic vascularr distance causing worsening of the high to left shunting

untreated child tends to squat a lot

failure to thrive

nail clubbing

dyspnea and tachypnea

Question 5

physical findings in tetralogy of fallot?

Answer 5

harsh systolic ejection murmur - erbs point
intensity increases in squatting
decreases with malformation progression

pulse oximetry reduces

Question 6

diagnosis of tetralogy of fallot?

Answer 6

echo
supplementary cardiac catheterisation can be performed

chest X ray
boot shaped heart
concave pulmonary artery segment
normal or decreased pulmonary vascular markings

ECG
right axis deviation
right atrial enlargement - P pulmonate

prominent R waves in V1-V2 (
Anterior)

S wave talk in v5-v6

reduced pulse oximetry

hyperoxia test - distinguish between pulmonary or cardiac cause
PaO2 is measured during the administration of 100% oxygen

Question 7

treatment for tetralogy of fallot?

Answer 7

severe RVOT - give IV prostaglandin until surgery

acute hypoxia - such as tet spells
- administer oxygen = dilated pulmonary vessels and constricts systemic vessels
knee to chest position squatting - shifts SVR and blood flow to pulmonary circulation
IV morphine for sedation
IV fluids

if the above measures fairl - IV beta blockers - propranolol

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treatment for heart failure
diuretics - furosemide
ionotropic drugs - digoxin
ACE INHIBITORS NOT RECOMMENDED BECAUSE IT CAN DECREASE SVR and promote set spells

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long term managmnet 
surgery : VSD repair 
correct aortal positioning 
enlargement of the RVOT : resection of the obstructive infundibular musculature

early surgical management is not possible: palliative shunts
connects the subclavian artery to the pulmonary artery

Question 8

ETIOLOGY OF Transposition of the great arteries

Answer 8

Often multifactorial or unknown

Intrauterine risk factors: infants born to mothers with diabetes

Genetic syndromes: seen in ∼ 1% of patients with DiGeorge syndrome

Question 9

clinical features of all other left to right shunts? ?

Answer 9

Postnatal cyanosis
Tachypnea
poor feeding
Failure to thrive

Question 10

physical findings in TGA?

Answer 10

Single, loud S2
NO MURMUR

Diminished femoral pulses

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usually can be associated with other cardiac defects such as
VSD
left ventricular outlet obstruction

Question 11

diagnosis of TGA?

Answer 11

echo

chest X ray
egg on string appearance of the heart
increased pulmonary vascular markings

ECG
often normal
or right axis deviation
and right ventricular hypertrophy

pulse oximetry
reduced oxygen saturation

Question 12

what is the treatment of TGA?

Answer 12

Initial postnatal management
pge1 INFUSION TO PREVENT PDA
or balloon atrial septostomy with right heart cathterisation
(to enhance atrial mixing if pge1 administration is insufficient )

surgical repair within first two weeks of life

Question 13

tricuspid atresia is usually accompanied by ?

Answer 13

RV hypoplasia and RA dilation due to volume overload

associated with tricuspid valve atresia
ASD
VSD
Circulation depends on the presence of interatrial and interventricular communications.

Question 14

physical findings in TRicuspid A?

Answer 14

Holosystolic murmur - lower left sternal border
When there is vsd

Single s2

Jugular venous distention

Diminished iperipheral pulses

Question 15

diagnosis of TRicuspid Atresia

Answer 15

Echocardiography (confirmatory test)
Absent tricuspid valve
ASD
RV hypoplasia

ECG
LVH with left axis deviation
Tall P waves - ra enlargement
Minimal R waves in precordial leads

Pulse oximetry: ↓ SpO2

Question 16

treatment of TVA?

Answer 16

PGE1

Cardiorespiratory support (e.g., inotropes, mechanical ventilation

surgical correction
Risk of pulmonary hypertension: pulmonary artery banding to control pulmonary hyperperfusion

In cases with concurrent pulmonary valve atresia or severe stenosis: systemic-to-pulmonary shunt (Blalock-Taussig shunt) to improve perfusion
subclavian artery and pulmonary artery

Question 17

etiology Truncus arteriosus?

Answer 17

di george syndrome

Question 18

Other cardiac defects associated with persistent truncus arteriosus?

Answer 18

VSD

Question 19

clinical features if truncus arteriosus?

Answer 19

Respiratory distress

Failure to thrive

Question 20

what are the physical findings of truncus arteriosus?

Answer 20

Bounding peripheral pulses

Harsh systolic murmur at the lower left sternal border

Loud S2

Question 21

diagnose of truncus arteriosus ?

Answer 21

echocardiography
chest x ray
- right sided aortic arch
absent thymus if associated with di george syndrome

pulse oximetry - reduced oxygen saturation

Question 22

treatment of truncus arteriosus ?

Answer 22

Prostaglandin Infusion

Treatment of Pulmonary Congestion and CHF
Use loop and thiazide diuretics

respiratory distress- ositive-pressure support (CPAP,

surgical correction before three months

Risk of pulmonary hypertension: pulmonary artery banding to control pulmonary hyperperfusion

Question 23

what is total anomalous pulmonary venous return ?

Answer 23

All four pulmonary veins drain into the systemic venous circulation (e.g., SVC, sinus venosus, RA, IVC) instead of the left atrium.

Other cardiac defects associated with TAPVR: allow for right-to-left shunting and the mixing of deoxygenated and oxygenated blood
ASD
PDA

Question 24

clinical features of anomalous pulmonary venous return?

Answer 24

Respiratory failure
Poor feeding and failure to thrive
Hepatomegaly

Question 25

physical findings of anomalous pulmonary venous return?

Answer 25

Fixed split S2
loud S2

Systolic ejection murmur with diastolic rumble

Question 26

diagnosis of anomalous pulmonary venous return ?

Answer 26

Pulse oximetry: ↓ SpO2

Echocardiography
Malposition of pulmonary veins
Enlarged right heart

Chest x-ray
“Snowman sign” (seen in supracardiac TAPVR): the orientation of the heart and superior mediastinum appear as the shape of a snowman
Pulmonary hypervascularity
Right heart enlargement

ECG
Right axis deviation due to RVH