Tof

Tetralogy of Fallout
JERIN.T.S, 3RD YEAR BSC NURSING, KRSMCON MANGALORE. PH:
+919496743672

 It is the most common cyanotic heart defect, and the
most common cause of blue baby syndrome
 It was described in 1672 by Niels Stensen, in 1773 by
Edward Sandifort, and in 1888 by the French physician
Étienne-Louis Arthur Fallot, after whom it is named.
+919496743672

TOF is the most common type of cyanotic congenital heart
disease. There are several forms of this defect, the
common ones are :
1) Obstruction to right ventricular outflow (pulmonary
stenosis)
2) Ventricular septal defect ( VSD )
3) Dextral position of the aorta with septal override/
overriding of aorta
4) Right ventricular hypertrophy
+919496743672

Pathophysiology
 Pulmonary stenosis and VSD are the
most vital abnormalities in TOF. The
defect largely depends on the stenosis
of pulmonary artery, VSD size,
pulmonary & systemic resistance to
the blood flow.
 If pulmonary artery resistance is more
than systemic, right to left shunt.
 If systemic vascular resistance is more
than pulmonary artery resistance, left
to right shunt.
+919496743672

Blood from systemic circulation
↓
Right atrium
↓
Right ventricle ( through VSD)and pulmonary artery resistance
↓
Left ventricle and Aorta
↓
Right to left shunt
↓
Cyanosis
↓
Polycythemia ( compensation)
↓
Increased viscosity of the blood
↓
Slowing down of circulation
↓
CVAJERIN.T.S, 3RD YEAR BSC NURSING, KRSMCON MANGALORE. PH:
+919496743672

Clinical features
Cyanosis:
 Neonates may not be cyanotic if the defects are very small ( because of
PDA)
 Cyanosis becomes evident after the ductus closes during the 1st
month
of life.
 Its evident in mucus membrane of mouth, lips, fingernails, & toe nails.
 Initially it is seen only during crying and exertion later seen even at rest
 Clubbing occurs by 1- 2 yrs
+919496743672

 Severe dyspnoea on exertion or exercise
 Rest in between the activities ( as compensation to reduce demand for 02)
(they sit or lie down after a brief active play)
 Knee chest position by infants
 Squatting position by older children
+919496743672

+919496743672

Paroxysmal dyspnoic attack
( anoxic “blue” spells) ( TET spells) (hypercyanotic spell)
 An episode of intense cyanosis that occurs
predominantly in morning after awakening from
sleep, during or after crying, during or after
defecation, during or following feeding
 Child starts crying becomes Dyspnoic & restless
 Gasps for breath
 Weak cry followed by sleep
Some times may cause convulsions and
unconsciousness
+919496743672

Cyanotic spells
+919496743672

 Prolonged episodes may
lead to
 Unconsciousness
 Convulsions
 Hemiparesis
 Death
+919496743672

 Slow growth and development
 Slow mental development because of tissue hypoxia of brain
 On auscultation murmurs heard
 Radiography shows enlarged ventricles on right side, large aorta &
decrease size of pulmonary artery.
 Cardiac catheterization shows hypertension in right ventricle
+919496743672

Diagnostic measures
1. Hematocrit increased-Polycythemia
2. ECG: shows right axis deviation
3. 2D Echocardiography, color flow mapping & doppler
4. Cardiac catheterization
5. Ventriculography
6. Chest X-ray: reveals oligemic lung fields (poorly vascularized lungs) a
small boot shaped heart with the tip of the boot turned up above the
diaphragm.
+919496743672

The abnormal "coeur-en-sabot"
(boot-like) appearance
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Medical Management
1. Prostaglandin E (0.05-0.20 µg/kg/min) IV to
maintain the patency of ductus
2. Management of spells, mild sedative like
promethazine reduces the frequency of spells,
provided it is given regularly.
3. Oral propranolol 0.5-1mg/kg oral every 6hrly
4. Treatment of iron deficiency anemia and
dehydration
5. Antibiotic therapy for bacterial infection
+919496743672

Management of TETspells
1)Treated with beta-blocker such as
propranolol, but acute episodes may
require rapid intervention with morphine
to reduce ventilatory drive and a
vasopressor such as epinephrine,
phenylephrine, or norepinephrine to
increase blood pressure.
2)Oxygen (100%) is effective in treating
spells because it is a potent pulmonary
vasodilator and systemic vasoconstrictor.
This allows more blood flow to the lungs.
+919496743672

Conti………
There are also simple procedures such as squatting and the
knee chest position which increases aortic wave
reflection, increasing pressure on the left side of the
heart, decreasing the right to left shunt thus decreasing
the amount of deoxygenated blood entering the
systemic circulation.
+919496743672

Stepwise management of
hypercyanotic spells
1) Put the child in knee chest position
2) Provide humidified O2-6-8L/min
3) Inject Morphine 0.1-0.2mg/kg S/C
4) Obtain arterial pH. If less than 7.3,
administer NaHCO3 1ml/kg diluted 1:1 in
distilled H2O IV
5) Give propranolol 0.1mg/kg IV during spell,
followed by 1mg/kg/day orally
6) Correct anemia by packed cell transfusion.
Start the child on long term oral iron
therapy.
+919496743672

Surgical management
palliative surgeries
To increase the pulmonary blood circulation
1. Waterson shunt: a side to side anastomosis of the
ascending aorta and right pulmonary artery in
neonates
2. Blalock taussig procedure: for older infants and
children, in which an artificial ductus is created by
anastomosis of a branch of the aorta ( subclavian
artery) to the pulmonary artery.
+919496743672

Modified Blalock-Taussig Shunt:by using Gortex Graft.
Avoid BP measurements and venipunctures in the affected arm after a
Blalock-Taussig shunt. Pulse will not be palpable in that arm because of
use of the subclavian artery for the shunt.
+919496743672

3. Potts procedure: anastomosis of the upper descending aorta and left
pulmonary artery
4. Brock procedure: is a direct operation, pulmonary valvotomy or
infundibular resection, for the pulmonary stenosis. This operation
increases pulmonary blood flow but does not correct the ventricular
septal defect.
+919496743672

Total surgical repair
 Surgery is now often carried out in
infants one year of age or younger with
less than 5% perioperative mortality.
 The open-heart surgery is designed
(1) to relieve the right ventricular outflow
tract stenosis by careful resection of
muscle and
(2) to repair the VSD with a Gore-Tex patch
or a homograft. Additional reparative or
reconstructive surgery may be done on
patients as required by their particular
cardiac anatomy.
+919496743672

Corrective surgery
Aims:
 To close the VSD
 To correct the pulmonary artery stenosis by
valvotomy
 To close the already created shunts
monitor for ventricular arrhythmias after corrective
repair.
+919496743672

Corrective surgery
+919496743672

Transposition of the Great
Arteries
TGATGA occurs when the pulmonary artery originates from the
left ventricle and the aorta originates from right
ventricle.
Accounts for 5% of total CHD
+919496743672

Hemodynamics
 The defect results in 2 separate
circulations
 The right side of the heart manages the
systemic circulation
 The left side of the heart manages
pulmonary circulation
 To sustain life there must be
accompanying defects (shunts) where
oxygenated blood mixes with
deoxygenated blood like ASD, VSD, OR
PDA
+919496743672

Pathophysiology
Blood from the systemic circulation
↓
Rt atrium, & Rt ventricle
↓
Aorta
↓
Deoxygenated blood supplied to the body
↓
Cyanosis
↓
Polycythemia
↓
Thrombi
↓
CVA
+919496743672

Oxygenated blood from the lungs
↓
Lt Atrium, Lt Ventricle
↓
Pulmonary artery
↓
Again circulates to the lung
But
when there is Shunt for mixing of oxygenated & deoxygenated blood
↓
Delays cyanosis
But
these associated defects can lead to increased pulmonary blood flow that
increases pressure in the pulmonary circulation
↓
CCF
+919496743672

Clinical features
Depends upon the inter circulatory
mixing
 Cyanosis
 Clubbing
 CCF
 Easy fatigability
 Slow weight gain
 Failure to thrive
 Frequent chest infections
 Tachypnea
 Cardiomegaly
+919496743672

Diagnosis
 Auscultation- systolic murmur
 Chest X-ray- cardiomegaly with a typical egg-on-side
shaped heart. Pulmonary vascular markings are
increased
 ECG shows right axis deviation, right or biventricular
hypertrophy
 Cardiac catheterization shows O2 saturation
 2D`echo reveals transpositions
+919496743672

Nursing measures
 Administer prostaglandins to maintain the open state of
the ductus arteriosus, which will allow the mixing of
poorly oxygenated blood with well oxygenated blood
 Monitor for rapid respiration and cyanosis
 Administer oxygen as needed preoperatively.
 Treat CCF timely
+919496743672

Surgical management
 Palliative – by balloon atrial septotomy
Is done soon after diagnosis to enlarge
the atrial septum. And it is successful
only when done within 6-12 weeks.
 Definitive- by arterial switch operation
or by redirecting the blood flow
Mustard or Senning procedure:in which
pulmonary venous blood is redirected
to the right ventricle and systemic
venous blood is redirected to the left
ventricle.
+919496743672

2) Jantene’s switch operation: the pulmonary artery and aorta are
transected. The distal aorta is anastomosed to the proximal pulmonary
stump and the pulmonary artery to the proximal aortic stump. The
coronary arteries are shifted to aorta. This surgery is preferred over other
surgery.
+919496743672

Complications
 Infective endocarditis
 Brain abscess and CVA due to thrombi or severe hypoxia
+919496743672

Tof

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