Relationship of QT Dispersion to Echocardiographic Left Ventricular Function, Dimension and Mass in Patients with Coronary Artery Disease

ABSTRACT

BACKGROUND: Previous studies showed that increased QT dispersion has been observed during episodes of myocardial ischemia or infarction and identified the patients at risk of arrhythmia or sudden death. The aim of this study was to investigate the relation between QT dispersion and left ventricular (LV) function (systolic and diastolic), dimension and mass as well as to analyze the differences of this relationship according to the extent of angiographic coronary stenosis in patients with coronary artery disease. METHODS: The study population included 262 patients (male 129, female 133;average age 60 years). Echocardiography was done for the measurement of left ventricular function, dimension and mass on admission. Electrocardiography for QT and QTc (corrected QT) dispersion were recorded 25 mm/sec paper speeds before the coronary angiography. Patients were divided into two groups; Group A where angiographic coronary stenosis or =50%. RESULTS: The results were as follows: 1) QT dispersion was higher in those with depressed LV systolic function (EF or =50%) of the coronary artery were independent prognostic factors of prolonged QT dispersion (p<0.05). 6) QTc dispersion showed the same result as QT dispersion. CONCLUSION: LV systolic function (EF), some diastolic function (IVRT), dimension (LVDd, LVDs, LAD IVS), and mass are associated with the increased QT dispersion in patients with coronary artery disease, especially minimal angiographic stenosed (<50%) patients. So, we consider echocardiography is an important tool to predict the QT dispersion in patients with coronary artery disease.