Effect of Transient Myocardial Ischemia on QT Interval Dispersion Among Patients with Unstable Angina

Authors

  • Konstantinos A Gatzoulis First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Dimitris Tsiachris First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Ioannis Mamarelis First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Petros Arsenos First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Apostolos Vouliotis First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Panagiota Pietri First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Stefanos Archontakis First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Skevos Sideris State Department of Cardiology, Hippokration Hospital, Athens, Greece
  • Polichronis Dilaveris First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece
  • Ioannis Kallikazaros State Department of Cardiology, Hippokration Hospital, Athens, Greece
  • Christodoulos Stefanadis First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

DOI:

https://doi.org/10.2015/hc.v7i2.441

Keywords:

QT interval dispersion, unstable angina

Abstract

Objective: Our aim was to examine the effect of transient myocardial ischemia on QT interval and QT interval dispersion in patients presenting with unstable angina.
Methods: We studied 31 patients (mean age 64±10, 22 men, 16 with an old myocardial infarction, 6 with previous coronary bypass surgery) admitted with unstable angina manifestations. Patients with a history of complex ventricular ectopy, malignant ventricular arrhythmias, advanced congestive heart failure or antiarrhythmic drug therapy were excluded. The uncorrected and corrected QT interval and QT dispersion were measured during angina as well as after the relief of pain.
Results: The RR intervals were not significantly changed by the ischemic event (879±121 ms at rest to 877±173 ms during angina). However, both the uncorrected and corrected QT intervals were significantly increased during angina (from 410±45 ms and 440±41 ms at rest to 425±53 ms and 460±42 ms during angina respectively, p<0.05 for both). Similarly, both the uncorrected (QTd) and the corrected (QTcd) QT dispersion values were significantly prolonged during ischemia (QTd: 58±23 ms at rest to 83±33 ms during ischemia, p<0.001, QTcd: 63±26 ms at rest to 95±36 ms during ischemia, p<0.001). The observed increment in the QTd and QTcd provoked by ischemia was not different among the unstable angina patients with and without old myocardial infarction.
Conclusion: Transient myocardial ischemia besides an increase in the QT and QTc intervals provokes an increase in both the corrected and uncorrected QT interval dispersion. Under certain circumstances, this may contribute to the genesis of serious reentry ventricular arrhythmias.

Author Biographies

Konstantinos A Gatzoulis, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Associate Professor of Cardiology

Dimitris Tsiachris, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Cardiologist

Ioannis Mamarelis, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Cardiologist

Petros Arsenos, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Fellow in cardiology

Apostolos Vouliotis, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Fellow in cardiology

Panagiota Pietri, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Fellow in cardiology

Stefanos Archontakis, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Fellow in cardiology

Skevos Sideris, State Department of Cardiology, Hippokration Hospital, Athens, Greece

Consultant Cardiologist

Polichronis Dilaveris, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Consultant Cardiologist

Ioannis Kallikazaros, State Department of Cardiology, Hippokration Hospital, Athens, Greece

Director

Christodoulos Stefanadis, First Cardiology Department, University of Athens Medical School, Hippokration Hospital, Athens, Greece

Professor of Cardiology

Downloads

Additional Files

Published

2012-01-28

Issue

Vol. 7 No. 2 (2012)

Section

ORIGINAL ARTICLES

License

Authors who publish with this journal agree to the following terms:

a. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.

b. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.

c. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).