The effect of coronary slow flow on ventricular repolarization parameters

Introduction: Ischemia due to microvascular dysfunction may be responsible for the heterogeneity of ventricular repolarization in coronary slow flow. To our knowledge, there is no study in which QT interval, Tp-Te interval, index of cardiac-electrophysiological balance (iCEB), and frontal QRS-T angle were evaluated together in pa-tients with CSF. In this study, we examined for the first time the relationship between all these myocardial repolarization parameters and CSF.Materials and methods: The study group included 178 patients (99 female, mean age: 50.6 +/- 8.6 years) with isolated CSF without stenotic lesions and with angiographically proven normal coronary arteries. The control group included 120 patients (71 female, mean age: 49.3 +/- 9.4 years) with normal coronary angiography. QRS duration, QT interval, QTc interval, Tp-Te interval, Tp-Te/QT, Tp-Te/QTc, iCEB score, and frontal QRS-T angle were calculated from 12-lead ECGs.Results: There was no significant difference in demographic parameters between the two groups. Compared with the control group, patients with CSF had significantly longer QTmax duration, QT dispersion, Tp-Te interval, and higher iCEB score, wider frontal QRS-T angle.Conclusion: In our study, we found that many of the ventricular repolarization parameters were adversely affected in patients with CSF. Impaired parameters may be associated with the risk of malignant ventricular arrhythmias.