What is Tetralogy of Fallot?
Tetralogy of Fallot (te – tra – lo – je of fah – low) is a heart defect that is present at birth (congenital). It is the most common heart defect in children affecting 5 out of every 10,000 babies born, and boys and girls equally. (1)
A baby/child is diagnosed with Tetralogy of Fallot when four particular defects are present at the same time:
• Ventricular Septal Defect (VSD) – VSD is a hole in the ventricular septum. The ventricular septum is a wall that separates the two lower halves of the heart, allowing oxygen-poor blood from the right ventricle to mix with oxygen-rich blood from the left ventricle.
• Pulmonary Stenosis – Pulmonary stenosis occurs when the pulmonary valve does not fully open, most often because of an obstruction. Not only does the heart have to work harder to pump blood through the valve through the pulmonary artery and into the lungs, but there is also less blood being pumped into the lungs.
• Right Ventricular Hypertrophy – Right ventricular hypertrophy occurs when the muscle of the right ventricle is thicker than normal. This thickening is caused by the extra work of pushing blood through the narrower pulmonary valve.
• Overriding Aorta – The aorta is normally attached to the left ventricle and is responsible for allowing only oxygen-rich blood to flow to the rest of the body. “In tetralogy of Fallot, the aorta is located between the left and right ventricles, directly over the VSD. As a result, oxygen-poor blood from the right ventricle flows directly into the aorta instead of into the pulmonary artery.” (1).
You can see the difference between a normal heart and a tetralogy of Fallot heart
Symptoms of Tetralogy of Fallot
A baby born with tetralogy of Fallot may not initially present with any obvious symptoms. Symptoms may appear over time and include:
• Bluish tinge to the skin (cyanosis)
• Shortness of breath and rapid breathing, particularly during feeding or physical activity
• Fainting spells