Fallot’s tetralogy

Published on 02/04/2015 by admin

Filed under Internal Medicine

Last modified 02/04/2015

Print this page

rate 1 star rate 2 star rate 3 star rate 4 star rate 5 star
Your rating: none, Average: 0 (0 votes)

This article have been viewed 1101 times

29 Fallot’s tetralogy

Instruction

Examine this patient’s heart.

Salient features

History

• Syncope (in 20% of cases)

• Squatting

• Shortness of breath

• Decrease in exercise tolerance

• Growth retardation.

Examination

• Clubbing

• Central cyanosis

• Left parasternal heave with normal left ventricular impulse

• Second sound is single (absent second pulmonic sound)

• Ejection systolic murmur heard in the pulmonary area

• Signs indicating Blalock–Taussig shunt:

• The left radial pulse is not as prominent as the right
• The arm on the side of the anastomosis (usually the left) may be smaller than the other arm
• Blood pressure is difficult to obtain because of the narrow pulse pressure in the arm supplied by the collateral vessels
• Thoracotomy scar.

Diagnosis

This patient has Fallot’s tetralogy with a Blalock–Taussig shunt and is mildly cyanosed, indicating a right to left shunt (functional status).

Questions

What are the constituents of Fallot’s tetralogy?

• Ventricular septal defect with a right-to-left shunt

• Pulmonary stenosis (infundibular or valvular)

• Right ventricular hypertrophy

• Dextroposition of the aorta with it overriding the ventricular septal defect.

What are the complications of Fallot’s tetralogy?

• Cyanotic and syncopal spells

• Cerebral abscess (in 10% of cases)

• Endocarditis (in 10% of cases)

• Strokes: thrombotic secondary to erythrocytosis and hyperviscosity

• Paradoxical emboli.

Advanced-level questions

What anomalies may occur in association with tetralogy of Fallot?

• Right aortic arch in 25% of patients

• Atrial septal defect in 10% (so-called pentalogy of Fallot)

• Coronary arterial anomalies in 10%.

What do you understand by a Blalock–Taussig shunt?

It is the anastomosis of the left subclavian artery to the left pulmonary artery with the intention to increase pulmonary blood flow.

Why is a Blalock–Taussig shunt seen less frequently in adults in the recent past?

With ready availability of cardiopulmonary bypass, such patients have total correction of their anomalies at an early age.

What is the survival of Fallot’s Tetralogy?

The rate of survival in uncorrected patients (Am J Cardiol 1978;42:458–66) is:

66% at 1 year of age

40% at 3 years

11% at 20 years

6% at 30 years

3% at 40 years.

Buy Membership for Internal Medicine Category to continue reading. Learn more here

Related posts:

Default ThumbnailSixth cranial nerve palsy Osteoarthrosis Cataracts Ebstein’s anomaly Paget’s disease Erythema nodosum