| ID | 382 |
|---|---|
| Name | TETRALOGY OF FALLOT (The commonest cyanotic congenital heart disease in children over the age of 1 year.) |
| Cause | |
| Signs Symptoms | |
| Diagnosis | |
| Investigations | Investigations: 1. Laboratory findings: Hb%, hematocrit & RBC count are usually mild to markedly elevated. 2. Imaging: chest x-ray- small or normal size heart. The heart shadow appears a boot shaped or ‘wooden shoe (coeur en sabot)’ with concavity of the left border in the region of the pulm. artery, rounded apex, which is raised or situated high above the left diaphragm. Aorta- in 20% cases the aorta arches to the right instead of left. Lung field- the hilar areas & lung fields are relatively clear due to diminished blood flow. 3. ECG: right axis deviation; rt. ventricular hypertr-ophy. T- wave may be positive (+ve) in the chest leads. P- wave is tall & peaked or some times bifid in chest leads. 4. Echocardiogram- reveals thickening of the free right ventricular wall, with over riding of the aorta and a membranous ventricular septal defect- which is diagnostic. 5. Cardiac catheterization & angiocardiography. |
| Management | Management: A. Medical management (there may not be any problem in the first year, but in some cases of severe tetralogy patients may require medical management in the early life). Aim- to provide an immediate increase in pulm. blood flow to prevent the sequele of severe hypoxia. 1. Patient should be transferred to a well equipped specialized medical centre to evaluate & treat the baby (if any problem arise) under optimal condition. 2. Maintenance of oxygenation & body temp, specially during transfer. 3. Maintenance of patency of Ductus arteriosus by Prostaglandin-E (a potent & specific relaxant of ductal smooth muscle)- to be given i.v. & continued until diagnosis is established & also continued through surgery & post operatively to augment the palliative shunt. (However it is not used for longterm therapy. 4. Maintenance of hydration & prompt treatment of dehydration to avoid hemoconcentration & possible thrombotic episodes (due to polycythemia). 5. Management of paroxysmal hypercyanotic attacks (blue spells)- a. Place the infant on knee-chest position over the shoulder of attendent (by this position venous return can be cut down & blue spells can be overcome) b. 02 inhalation by face mask, c Inj. morphine 0. l-0.2mg/kg s.c or i.v. Or, d. Inj. propranolol 0.1-0.2mg/kg i.v specially in severe spells with tachycardia. (Morphine helps by dilating the stenosed pulm. valves & increases pulm. circulation). e. In metabolic acidosis- it should be corrected with inj. sodi-bicarbonate. f. As it is precipitated by iron deficiency anemia- iron therapy should be given. Hem-atocrit should be maintained at 55-65%. g In older infants squatting position is an alternative to knee-elbow position, h. If with above measure spells are not controlled palliative measure should be undertaken. B. Surgical management - two parts. 1. Palliative surgery i.e. shunt procedure e.g, Blalock-Taussing shunt (most useful shunt procedures). 2. Corrective surgery- a total correction of all the defects by open heart surgery using a heart-lung bypass machine. Palliative surgery is safest at 1 yr. of age & total correction is indicated before school age. |
| Introduction | Anatomy: Tetralogy of Fallot consists of- 1. Pulmonary stenosis (rarely atresia). 2. V.S.D. 3. Dextropostion of aorta. 4. Right ventricular hypertrophy. There are many variations of anomalies depen-ding upon the degree and type of pulm. stenosis; size of the VSD & the degree of aortic dextroposition (e.g in some instances, the aorta may open totally to the right ventricle i.e. it. sided aorta). |
| History | |
| Etiology | |
| Clinical Features | Clinical manifestations: Manifestations of fallot usually become prominent after the age of 4 years in 75% cases. 1. Cyanosis- central type- in mild cases cynaosis may not present at birth or in the early first year. 2. Dyspnoea- usually on exertion or play take frequent rest in a very characteristic squatting position. 3. Hypoxic or blue spells- these are paraoxysmal hyper cyanotic attacks occur particularly during the first two years of life. The infant becomes - hyperapnoic & restless - hypercyanotic - gasping respirations & - syncope may follow. Short episodes are followed by generalized weakness & sleep. Severe spells may progress to- - unconciousness - convulsion (occasionally) - hemiparesis. The spells may last from a few minutes to a few hours but are rarely fatal. The spells most frequently occur in the morning, but the onset is usually spontaneous & unpredictable. 4. Retardation of growth & development. 5. Clubbing & 6. Polycythemia. On palpation- 1. Pulse- rate, normal. Apex beat- not shifted. 2. Substernal rt. ventricular impulse. 3. Systolic thrill- in 50% cases, along the left sternal border in the 3rd & 4th parasternal spaces. 4. Left anterior hemithorax may bulge anteriorly. On Auscultation - 1. Systolic murmur-is frequently loud & harsh. Murmur may be either- a. Ejection systolic (due to P.S)- best heard at pulm. area, or b. Pansystolic (due to VSD)- best heard at left lower sternal border. 2. 2nd heart sound is single & is aortic component i.e A2. P2 is inaudible due to P.S |
| Preventions | |
| Treatment | |
| Complications | Complications of Pallet’s: 1. Cerebral ischemia. 2. Cerebral thrombosis. 3. Brain abscess. 4. Bacterial endocarditis. 5. Congestive heart failure. |
| Prognosis | Prognosis: 1. Only half of the children with Pallet’s survive their 3rd. birh day. Without surgical intervention. 2. The prognosis depends mostly on surgical management. 3. Surgical risks for total correction is under 10%. 4. There may be a sudden death (very rarely) with following a late onset complete heart block. |
| Types | |
| Classification | |
| Observation | |
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