Time course of the ST segment changes after electrical cardioversion of chronic atrial fibrillation

H. Y. Chen, J. I. Jiang, L. P. Lai, J. L. Lin, S. K. Stephen Huang

Research output: Contribution to journalArticlepeer-review


Background: Electrocardiographic (ECG) abnormalities have been reported after transthoracic direct-current electrical cardioversion. The ST segment elevations are especially problematic and may indicate cardiac injury or even mimic the life-threatening Brugada syndrome Materials and We studied the evolution of 12-lead ECGs after transthoracic electrical cardio Methods: version for chronic atrial fibrillation in 27 consecutive patients, Countershocks were administered by incremental energy levels starting from 50, 100, 200, 300 to 400 Joules(J). The changes of 12-lead ECGs were recorded after successful conversion or the maximum of 400 J. Results: Acute ST segment elevation occurred in 23 (85%) of the 27 patients with a mean amplitude of 0.51 ± 0.52 mV (range 0 to 2.1 mV). The ECG leads with the elevated ST segments were precordial in 19 patients, anterolateral in 7 and inferior in 15. The ST segment change persisted for 50.7 ± 44.5 seconds (range 3 to 182 seconds). The peak (r = 0.35,p = 0.082) and duration (r = 0.37, p = 0.080) of the ST segment elevation escalated gradually in proportion to the energy required for cardioversion. The morphology of ST segment elevation after cardioversion manifested as either a high plateau or a dome shape in 15 patients. Whereas, a coved or saddleback-shaped ST elevation at VI, V2 or V3 leads was recorded in 8 other patients, mimicking that of Brugada syndrome. However, the post-cardioversion ST change was always widespread, never clustered only at V1 to V3 leads, and resolved rapidly within 44.2 ± 44.8 seconds (range 0 to 182 sec). On the other hand, the corrected QT interval became shorter in the post-cardioversion ST segment elevation phase (448.0 ± 55.7 ms, vs 496.4 ± 37.6 ms before cardioversion, p = 0.001) and in the ST segment recovery phase (467.9 ± 55.5 ms, p = 0.013, vs before cardioversion). There was no dispersion of the corrected QT interval nor the QRS interval after cardioversion. Conclusions: Postcardioversion transient ST elevation was usually manifested as a plateau or dome shape, less of a coved or saddle-back shape, and always disappeared within 3 minutes.

Original languageEnglish
Pages (from-to)17-26
Number of pages10
JournalActa Cardiologica Sinica
Issue number1
Publication statusPublished - Jan 1 2001
Externally publishedYes


  • Atrial fibrillation
  • Brugada syndrome
  • ECG
  • Electrical cardioversion

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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