Cyanotic Heart Conditions

What causes cyanotic conditions?

There may be a number of different causes of cyanotic conditions but there are some that are more common than others; these include:

  • Tetralogy of Fallot (also known as TOF): this is the most common cause of cyanotic conditions. This condition involves four defects that affect the structure of the heart; these include a tiny hole between the left and right ventricles, abnormal thickening of the muscles in the right ventricle, the pulmonary valve becoming too narrow and a displaced aortic valve. The defects cause the blood with a high percentage of oxygen and blood with a low percentage of oxygen to mix together; the blood that is then pumped around the body has lower oxygen content than normal.
  • Transposition of the Great Arteries (TGA): this is the second most common cause of cyanotic conditions. This condition is caused by the pulmonary and aortic valves being in the wrong place; this results in low oxygen levels in the blood.
  • Diabetes (in the mother): mothers with diabetes are much more likely (up to 5 times) to give birth to a baby with a congenital heart condition
  • Alcohol abuse (by the mother): drinking during pregnancy increases the risk of giving birth to a baby with a heart defect; it is estimated that between 30 and 50 percent of women that drink regularly throughout their pregnancy will give birth to a child with a congenital heart condition.
  • Rubella (in the mother): rubella, also known as German measles can be extremely dangerous for the health of the baby, especially during the first 12 weeks of the pregnancy; around 80 percent of mothers that develop the condition during this time will give birth to a child with a congenital heart condition.
  • Genetic conditions: genetic conditions such as Down’s syndrome, Turner syndrome and Noonan syndrome can all cause heart defects.

Symptoms of cyanotic conditions

Common symptoms of cyanotic conditions include:

  • Fainting
  • Pain in the chest
  • Blue colouring in the extremities (the fingers and toes) and the lips (this is also known as cyanosis)
  • Difficulties with breathing
  • Hypoxia: this occurs in periodical bouts when the body suddenly experiences a severe shortage of oxygen; this causes hyperventilation and cyanosis
  • Slow development and growth
  • Difficulties with feeding
  • Sweating

Heart Conditions

Heart Conditions Intro

Acyanotic heart conditions


Coronary heart disease

Cyanotic heart conditions

Valvular heart disease