Transient ischemic attack and acute ischemic stroke: evidence of altered corrected index of cardiac electrophysiological balance

Zhen HuChan GaoXiaoping YuAnkang YangLin ZhuYuying DengShuo ZhangYafei PengKuangrong SongLiangqiao ZhaoHanqin HuangJiajia Lu^*

• Wuhan No 1 Hospital, Wuhan, China

Background. Several electrocardiogram (ECG) abnormalities have been reported in patients with acute cerebral ischemic events. The index of cardiac electrophysiological balance (iCEB) and corrected index of cardiac electrophysiological balance (iCEBc) are potential non-invasive markers for arrhythmogenesis. Therefore, Chinese patients diagnosed with transient ischemic attack (TIA) or acute ischemic stroke (AIS) were included in this case-control study to explore the potential alterations in these markers and to determine the relationships between them and the National Institutes of Health Stroke Scale (NIHSS) score at admission. Methods. We performed a hypothesis-generating, exploratory analysis on retrospective data. Consecutive patients diagnosed with TIA or AIS at the Department of Neurology, Wuhan No. 1 Hospital, from January 2021 to June 2024, were included. Patients with bundle branch block, intraventricular conduction delay, ventricular pacing, ventricular rhythm, sino-ventricular conduction, atrial fibrillation or atrial flutter, Wolff-Parkinson-White, long QT syndrome, thyroid dysfunction, serum electrolyte imbalances, acute coronary syndrome, acute heart failure, severe valvular heart disease, cardiomyopathy were excluded from the study. There are several formulas for calculating QTc. Given the computational dependency of iCEBc on QTc values, we specifically investigated the potential formula-related effects of two variants: iCEBcB (based on Bazett's formula) and iCEBcF (based on Fridericia's formula). ICEB, iCEBcB, and iCEBcF were compared between groups. Regression analyses demonstrated connections between these variables and the NIHSS score in patients with AIS at the time of admission. Results. A total of 382 Chinese patients were enrolled in this study. There were 52 in the control group, 96 in the TIA group, and 234 patients in the AIS group. From the control group, through the TIA group, to the AIS group, both iCEBcB and iCEBcF demonstrated a gradual upward trend. Only iCEBcB showed an independent and positive correlation with the NIHSS score at admission. Conclusion: This study identified a graded increase in iCEBcB and iCEBcB across the clinical spectrum, from controls to TIA and further to AIS patients. An elevated iCEBcB emerged as a significant independent predictor of the NIHSS score at admission. ICEBcB could provide a non-invasive means of detecting early, subclinical electrophysiological abnormalities in patients with ischemic stroke.