Role of shortened QTc dispersion in in-hospital cardiac events in patients undergoing percutaneous coronary intervention for acute coronary syndrome

Chi Cheng Lai, Hsiang Chiang Hsiao, Shin Hung Hsiao, Wei Chun Huang, Chuen Wang Chiou, Tung Cheng Yeh, Hwong Ru Hwang, Doyal Lee, Guang Yuan Mar, Shih Kai Lin, K. R. Chiou, Shoa Lin Lin, Chun Peng Liu

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Abstract

Background: QT dispersion (QTD) refers to the difference between maximal and minimal QT values on the electrocardiogram (ECG). QTD values are calculated and corrected with Bazett's formula (corrected QTD = QTcD = QTD/ √RR). QTcD increases in patients with acute coronary syndrome (ACS). Recovery of increased QTcD (shortened QTcD) develops after successful revascularization, but prolonged QTcD occurs in certain patients. The aim of this study is to ascertain the clinical significance between shortened and prolonged QTcD groups after percutaneous coronary intervention (PCI). Methods: We retrospectively enrolled 128 patients with ACS who had received PCI. The values of QTcD were measured manually on 12-lead standard ECGs obtained within 3 days before and after PCI (pre-PCI QTcD and post-PCI QTcD). All the patients were divided into 2 groups. The shortened QTcD group was defined as those patients with a decrease in QTcD after PCI and the prolonged QTcD group as those with an increase in QTcD after PCI. The underlying diseases, various clinical classifications and some prognostic factors were taken into comparison and statistical analysis between these 2 groups. Results: The shortened QTcD group showed a significantly higher rate of in-hospital cardiac death (13% vs. 0%, p = 0.006) and a greater pre-PCI QTcD (100.8 ± 39.5 vs. 61.3 ± 24.1 ms, p < 0.001) than the prolonged QTcD group. There was a significantly greater pre-PCI QTcD in patients with cardiac death than those without cardiac death (111.6 ± 38.3 vs. 83.3 ± 38.3 ms, p = 0.027). Furthermore, the patients with in-hospital cardiac death presented with a significantly more frequent occurrence of in-hospital ventricular arrhythmia, compared with those without cardiac death (30.0% vs. 4.0%, p = 0.014). Conclusion: Among the patients with ACS undergoing PCI, directly divided into shortened and prolonged QTcD groups regardless of initial pre-PCI QTcD, the shortened QTcD group showed a higher occurrence of in-hospital cardiac death and a greater pre-PCI QTcD. Shortened QTcD might be 1 risk factor for in-hospital cardiac death.

Original languageEnglish
Pages (from-to)297-303
Number of pages7
JournalJournal of the Chinese Medical Association
Volume69
Issue number7
DOIs
Publication statusPublished - Jan 1 2006
Externally publishedYes

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Keywords

  • Acute coronary syndrome
  • Acute myocardial infarction
  • Cardiac death
  • Percutaneous coronary intervention
  • QT dispersion

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Lai, C. C., Hsiao, H. C., Hsiao, S. H., Huang, W. C., Chiou, C. W., Yeh, T. C., Hwang, H. R., Lee, D., Mar, G. Y., Lin, S. K., Chiou, K. R., Lin, S. L., & Liu, C. P. (2006). Role of shortened QTc dispersion in in-hospital cardiac events in patients undergoing percutaneous coronary intervention for acute coronary syndrome. Journal of the Chinese Medical Association, 69(7), 297-303. https://doi.org/10.1016/S1726-4901(09)70262-X