Tetralogy of Fallot Overview

What is the main cause of acute cyanosis and hypoxia in infants with Tetralogy of Fallot?

Why do hypercyanotic spells, or 'tet spells', occur in infants with Tetralogy of Fallot?

What is the purpose of squatting in children with Tetralogy of Fallot?

What is the definitive surgical intervention for Tetralogy of Fallot usually performed during the first year of life?

Which characteristic is often observed in children with increasing cyanosis due to Tetralogy of Fallot?

Tetralogy of Fallot

Acute cyanosis and hypoxia: Caused by infundibular spasm, which increases right-to-left shunting through the ventricular septal defect, reducing pulmonary blood flow and increasing cyanosis.

Hypercyanotic Spells ('Tet Spells')

Triggers: Infundibular spasm, dehydration, fever, or crying, which increase right-to-left shunting, reducing pulmonary blood flow and increasing cyanosis.
Symptoms: Sudden onset of deep blue discoloration, irritability, and increased respiratory rate.

Squatting in Children with Tetralogy of Fallot

Purpose: To increase systemic vascular resistance, which reduces right-to-left shunting and increases pulmonary blood flow, thereby decreasing cyanosis.

Definitive Surgical Intervention

Timing: Usually performed during the first year of life.
Procedure: Total correction of Tetralogy of Fallot, which involves closing the ventricular septal defect and relieving right ventricular outflow tract obstruction.

Characteristics of Increasing Cyanosis

Clubbing: Often observed in children with increasing cyanosis due to Tetralogy of Fallot, as a result of chronic hypoxia.

Learn about the four defects that make up Tetralogy of Fallot and how blood flow is affected depending on the balance of resistances. Understand the clinical presentation and progression of this congenital heart condition.