Q20.6: Isomerism of atrial appendages

The upper chambers (atria) of your heart did not develop properly before you were born.

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.

Normally, the left and right atrium differ from one another in their structure. Your atria are a mirror image of each other. This means that both of your atria look like either a left atrium or like a right atrium.

With this condition, you may also have other defects of the heart or other organs. In many cases, people with your condition are born with no spleen or with more than one.

This heart defect can cause various symptoms. The symptoms depend on what other defects are present. You may have breathing problems or tire quickly. The symptoms may begin shortly after birth.

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.


Provided by the non-profit organization “Was hab’ ich?” gemeinnützige GmbH on behalf of the Federal Ministry of Health (BMG).