Majalah Kardiologi Indonesia (Sep 2019)
Diagnostic Value Of Qtc Dispersion And And Qt Dispersion Ratio Changes On Stress Test In Detecting Significance Of Coroner Lesion In Stable Angina Pectoris Patients
Abstract
Background : Treadmill exercise test remains an important method and often used in the initial evaluation of patients with chest pain and can be a filter for more expensive invasive diagnostic. Increased QT dispersion (QTD) occurs because of the heterogeneity of ventricular repolarization because transient ischaemia during a treadmill stress test can be a marker of coronary artery disease (CAD) and can improve the accuracy of exercise tests to diagnose CAD, but this parameter is still controversial. Method : This is an analytic observational approach with a cross sectional study. Data was taken retrospectively at the Heart Center Installation at RSUP Dr. M. Djamil Padang, from March to April 2019, stable angina pectoris patient with a positive treadmill stress test who underwent coronary angiography as the subject. Bivariate analysis was performed on changes in QTcD (∆QTcD) and QTdR (∆QTdR) variables on the significance of coronary lesions by the chi-square method, after which a diagnostic test was based on receiver operating curve (ROC) analysis. Study Result : There were 122 subjects and found that older age, male and smoking were more common in groups with significant coronary lesions. Cut off point for ∆QTcD is ≥13 ms with a sensitivity of 87,1% and specificity 85,2% and AUC 95,1%, while ∆QTdR ≥5.5% with sensitivity 85,7% and specificity 81,9% and AUC 90,5% are related to significancy of coronary lesion. Obtained subjects with significant lesions generally had a value of ∆QTcD ≥ 13 ms (p <0.001) and ∆QTdR ≥ 5.5% (p <0.001). Conclusion : The use of ∆QTdR dan ∆QTdR parameters as ECG variables, which are easily obtained in evaluating stress tests, can improve the diagnostic accuracy of exercise tests. In addition, evaluation of ∆QTdR dan ∆QTdR can provide information about the incidence of CAD. Keywords : ∆QTcD, ∆QTdR, Treadmill Exercise Test, Coronary Lession Significancy
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