Bacckground: QT interval represents duration of ventricular systole containing of 2 depolarization and repolarization phases, varies in duration in different leads of EKG normally due to variation of repolarization and re-excitability of different ventricular regions. QT dispersion defined as difference between maximum and minimum of QT interval duration is supposed to be a strong predictor for myocardial viability in cardiac disorders particularly in ischemic heart diseases and myocardial infarction (MI).
Object: current systematic review of literature study aims to evaluate QT dispersion measurement as a simple and powerful prognostic test to predict risk of life-threatening arrhythmia and cardiac sudden death, and ventricular dysfunction in patients with MI. It also attends to show the reliability of QT dispersion in assessment of efficacy of reperfusion therapeutic strategies.
Method and materials: all prospective English trials with key words of QT dispersion, myocardial viability and myocardial infarction or MI were searched through Pubmed. Among 294 presented articles, 7 studies recognized eligible to enroll.
Results: application of QT dispersion for myocardial viability assessment was performed through 3 different categories in patients with MI. 1.prediction of life-threatening arrhythmia and cardiac sudden death. 2. Relation between QT dispersion values and ventricular wall motion. 3. evaluation of response to reperfusion therapeutic strategy by QT dispersion measurement.
Conclusion : according to data of reviewed studies QT dispersion is a reliable simple applicable tool for myocardial viability assessment in patients with MI.