I48.2: Chronic atrial fibrillation

Your heart’s atria are constantly beating too quickly and irregularly.

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. For the heart to be able to pump blood well, the atria and ventricles have to beat with a regular rhythm. Normally the atria and the ventricles beat at the same rhythm. Your heart’s atria are constantly beating too quickly and irregularly. This is called atrial fibrillation.

The heart's electrical activity causes the heart muscle to contract. It begins at a site in your right atrium. Initially the electrical activity spreads to both atria. The electrical activity then flows on via a sort of cable to the ventricles. With atrial fibrillation, the heart’s electrical activity gets mixed up. So with atrial fibrillation the atria beat far too quickly and irregularly. The irregular currents do not get routed evenly via the cable to the ventricles. So the ventricles may beat too quickly, too slowly, or normally. With atrial fibrillation, the ventricles usually also beat irregularly.

If the atria beat too quickly over a long period of time, it often goes unnoticed.

Atrial fibrillation can damage the heart. If the atria and ventricles do not beat regularly, the heart is sometimes unable to properly supply the body with blood. Atrial fibrillation can make the atria get larger. The blood is then sometimes unable to flow normally through the atria. Blood clots may form as a result. These blood clots can get swept away with the blood. The blood clots can then get stuck in other blood vessels in the body. This can cause problems.

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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