Q20.3: Discordant ventriculoarterial connection

Your aorta and pulmonary artery are switched in position. This condition is congenital, which means you were born with it.

The heart pumps blood through the body. Inside the heart are 4 chambers. There are 2 heart atria and 2 ventricles. Both heart atria and both ventricles are separated from each other by a partition. Major, important blood vessels branch out of the heart. The main artery (aorta), originating from the left lower chamber (ventricle) of the heart, supplies the whole body with oxygen-rich blood. The right ventricle pumps oxygen-poor blood through the pulmonary artery to the lungs, where the blood is then enriched with oxygen.

Your heart did not develop properly before you were born. As a result, your aorta originates from the right lower chamber (ventricle) of your heart. Your pulmonary artery originates from the left ventricle of your heart. The precise cause of this is not known. The oxygen-rich blood from your lungs is pumped directly back into the lungs from the left ventricle. At the same time, the oxygen-poor blood from your body is pumped directly back into the body from the right ventricle.

After birth, however, there are initially two places through which oxygen-rich blood can still get into the body. These are a connection between the main artery (aorta) and the pulmonary artery and a hole in the wall (septum) between the upper chambers (atria) of the heart. Normally, these places close up shortly after birth.

With this heart defect, the symptoms depend on factors such as how much blood is flowing through the two connections and when they close up. Shortly after birth, there may initially be no symptoms. However, symptoms may very quickly develop. The skin may then appear bluish in color and you may get exhausted quickly. Later, these may be accompanied by shortness of breath and other symptoms, including life-threatening ones.

Additional indicator

On medical documents, the ICD code is often appended by letters that indicate the diagnostic certainty or the affected side of the body.

  • G: Confirmed diagnosis
  • V: Tentative diagnosis
  • Z: Condition after
  • A: Excluded diagnosis
  • L: Left
  • R: Right
  • B: Both sides

Further information


This information is not intended for self-diagnosis and does not replace professional medical advice from a doctor. If you find an ICD code on a personal medical document, please also note the additional indicator used for diagnostic confidence.
Your doctor will assist you with any health-related questions and explain the ICD diagnosis code to you in a direct consultation if necessary.


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