Evaluation of index of cardio-electrophysiological balance in patients with coronary slow flow

Background Coronary slow flow (CSF) is defined as the late progression of applied contrast through coronary arteries. The cardiac electrophysiological balance index (iCEB) reflects the balance between ventricular depolarisation and repolarisation and provides more information about ventricular arrhythmogenesis (VA) than other electrocardiography (ECG) parameters (QT, corrected QT [QTc], etc.). Aim We aimed to evaluate iCEB in patients with CSF. Methods We divided the study population into two groups as CSF and control. The CSF group consisted of 100 patients (33 female, 67 male, mean age 52.2 +/- 2.6), while the control group consisted of the same number of age and sex-matched patients (35 female, 65 male, mean age 51.7 +/- 1.4). ECG parameters of the study population (QRS duration, QT, T wave peak-to-end (Tp-e) intervals, iCEB (QT/QRS), and iCEBc (heart rate QTc/QRS) rates were calculated and compared between CSF and control groups. Results Intervals (QT and QTc intervals) and Tp-e/QTc ratio were greater in the CSF group compared with controls [422.1 +/- 12.8 vs. 349.4 +/- 14.3 bpm, respectively, p < .001; 457.0 +/- 12.2 vs. 378.1 +/- 12.3 bpm, respectively, p < .001, and 0.19 vs. 0.12, respectively, p < .001]. ICEB and iCEBc were significantly greater than controls [(4.9 +/- 0.4 vs. 4.2 +/- 0.4, respectively, p < .001), (5.7 +/- 0.3 vs. 4.4 +/- 0.3, respectively, p < .001)]. Conclusions ICEB and iCEBc were significantly increased in patients with CSF. This may suggest that CSF may predispose to malign arrhythmias.