Tetralogy of Fallot

A 12 month-old child with tetralogy of Fallot is most likely to have which of the following clinical features? A. Chest pain B. Cyanosis C. Convulsions D. Palpitations

B. Cyanosis Cyanosis is very common in tetralogy of Fallot.

How is Tetralogy of Fallot repaired surgically?

Complete surgical repair with VSD closure and removal or patching of the pulmonary stenosis can be performed in infancy. Occasionally, palliative shunt surgery between the subclavian artery and pulmonary artery is performed for complex forms of tetralogy of Fallot and more complete repair is done at a later time.

What coronary anomalies are associated with Tetralogy of Fallot?

Coronary anomalies, most commonly a left anterior descending coronary artery arising from the right coronary artery and crossing the anterior surface of the right ventricular outflow tract, are present in 5% of patients with Tetralogy of Fallot.

What is a hereditary T-cell disorder that is associated with tetralogy of Fallot?

DiGeorge syndrome is a hereditary T-cell disorder that is associated with tetralogy of Fallot. -Caused by 22q11 deletion -Failure of 3rd and 4th pharyngeal pouch development -Thymic aplasia -Also associated with hypocalcemia which can lead to tetany -DiGeorge may also be associated with persistent truncus arteriosus

A 10-month-old girl was admitted to the hospital for cardiac catheterization. Her history included cyanosis noted at about 6 weeks of age, increasing over the last 7 months and becoming more severe with crying or physical activity. The chest x-ray demonstrates a "boot shaped heart" A presumptive diagnosis of tetralogy of Fallot (TOF) was made on admission. TOF has 4 components, which of the following below is not part of the diagnosis? A. Pulmonary valve stenosis B. VSD C. Overriding aorta D. Right ventricular hypertrophy E. ASD

E. ASD In 1888, Fallot described a congenital heart defect composed of four characteristics (a) large ventricular septal defect (VSD) (b) right ventricular outflow obstruction (pulmonary valve stenosis) (c) overriding aorta (d) right ventricular hypertrophy. The main characteristic of TOF is cyanosis. Hypercyanotic spells or "tet spells" are paroxysmal episodes in which the cyanosis acutely worsens. Crying, feeding, or defecating can bring on these episodes.

What is a useful mnemonic to remember the features of Tetralogy of Fallot?

Four features: PROVe P ulmonary Stenosis R ight ventricular hypertrophy O verriding aorta V entricular septal defect

What are complications of Tetralogy of Fallot?

Independent of hypoxic spells, patients with unrepaired Tetralogy of Fallot are at increased risk for cerebral thromboembolism and cerebral abscesses resulting, in part, from their right-to-left intracardiac shunt.

What is the heart murmur of Tetralogy of Fallot?

Infants initially may be acyanotic. A pulmonary stenosis murmur is the usual initial abnormal finding. The amount of right-to-left shunting at the VSD (and the degree of cyanosis) increases as the degree of pulmonary stenosis increase. With increasing severity of pulmonary stenosis, the murmur becomes shorter and softer. -Murmur is classically described as a harsh systolic ejection murmur heard best at the left sternal border. In addition to varying degrees of cyanosis and a murmur, a single S2 and right ventricular impulse at the left sternal border are typical findings.

What prophylaxis is indicated for patients with Tetralogy of Fallot?

Subacute bacterial endocarditis prophylaxis is indicated until 6 months after complete repair unless there is a residual VSD. Prophylaxis is then continued as long as there is a residual VSD.

Tetralogy of Fallot is characterized by what type of murmur?

Tetralogy of Fallot is characterized by the presence of a harsh systolic ejection murmur heard best at the left sternal border.

What is the etiology of Tetralogy of Fallot?

Tetralogy of Fallot is due to abnormal septation of the truncus arteriosus into the aorta and pulmonary artery that occurs early in gestation (3-4 weeks). The VSD is large, and the pulmonary stenosis is most commonly subvalvular or infundibular. It may also be valvular, supravalvular, or, frequently, a combination of levels of obstruction.

What is Tetralogy of Fallot?

Tetralogy of Fallot is the most common cyanotic congenital heart defect, representing about 10% of all congenital heart defects. There are four structural defects: ventricular septal defect (VSD), pulmonary stenosis, overriding aorta, and right ventricular hypertrophy.

What imaging studies are useful in evaluating Tetralogy of Fallot?

The electrocardiogram (ECG) usually has right axis deviation and right ventricular hypertrophy. The classic chest x-ray finding is a boot-shaped heart created by the small main pulmonary artery and upturned apex secondary to right ventricular hypertrophy. Echocardiography is the diagnostic modality of choice. Echocardiography shows the anatomical features, including the anatomical level and quantification of pulmonary stenosis.

What is the natural history of Tetralogy of Fallot?

The natural history of Tetralogy of Fallot is progression of pulmonary stenosis and cyanosis?

What type of shunt occurs in Tetralogy of Fallot?

The pulmonary stenosis causes a right to left shunt through the VSD, thereby causing cyanosis.

What determines the severity of the manifestations of tetralogy of Fallot?

The severity of the manifestations of tetralogy of Fallot is mainly dependent on the degree of pulmonary stenosis.

How is Tetralogy of Fallot treated?

Treatment of hypoxic spells consists of oxygen administration and placing the child in the knee-chest position (to increase venous return). Traditionally, morphine sulfate is given (to relax the pulmonary infundibulum and for sedation). If necessary, the systemic vascular resistance can be increased acutely through the administration of an alpha-adrenergic agonist (phenylephrine). The occurrence of a cyanotic spell is an indication to proceed with surgical repair.

What is the prognosis of Tetralogy of Fallot?

Twenty-year survival rates after surgery are above 80%. The most common causes of death are sudden cardiac death and heart failure. Complications after surgery include arrhythmias, pulmonary regurgitation, residual outflow obstruction, and heart failure.

How does Tetralogy of Fallot present clinically?

When hypoxic (Tet) spells occur, they are usually progressive. During a spell, the child typically becomes restless and agitated and may cry inconsolably. An ambulatory toddler may squat. Hyperpnea occurs with gradually increasing cyanosis and loss of the murmur. In severe spells, prolonged unconsciousness and convulsions, hemiparesis, or death may occur.