Egg-on-a-string sign (heart)

Dr Dan J Bell and Dr Aditya Shetty et al.

Egg-on-a-string sign, also referred to as egg on its side, refers to the cardiomediastinal silhouette seen in transposition of the great arteries (TGA).

The heart appears globular due to an abnormal convexity of the right atrial border and left atrial enlargement and therefore appears like an egg.

The superior mediastinum appears narrow due to stress-induced thymic atrophy and hyperinflated lungs which give the picture of an egg suspended by a string on a chest radiograph, hence the name egg-on-a-string.

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Article information

rID: 28508
Section: Signs
Tags: shetty, refs, cases
Synonyms or Alternate Spellings:
  • Egg on a string
  • Egg on a string sign
  • Egg on its side
  • Egg on side

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