Background: Ventricular arrhythmias are a major cause of mortality in patients with heart failure. Although implantable cardioverter-defibrillators (ICDs) reduce arrhythmic death, risk stratification remains suboptimal. This study aimed to evaluate the association between electrocardiographic ventricular repolarization parameters and malignant ventricular arrhythmias in patients with non-ischemic heart failure (NIHF).
Methods: This retrospective cohort study included 85 patients with NIHF who underwent ICD implantation between 2016 and 2022. Patients were categorized according to the occurrence of ventricular arrhythmias within three years after ICD implantation. Baseline electrocardiographic, echocardiographic, laboratory, and demographic data were compared between groups.
Results: Ventricular arrhythmias developed in 36% of patients. QT interval (430 ms, p < 0.001), QTc interval (439.7 ms, p < 0.001), Tpeak-Tend interval (Tp-e) (85 ms, p = 0.003), and QRS duration (112.8 ms, p = 0.013) were significantly prolonged in patients with arrhythmias. In multivariable regression analysis, QTc demonstrated the strongest association with ventricular arrhythmias. ROC analysis revealed a QTc cut-off value of 428.5 ms (sensitivity 74.2%, specificity 74.1%, AUC: 0.775, 95% CI: 0.675-0.876, p < 0.001). Sensitivity analysis after exclusion of amiodarone users showed persistence of the QTc association in univariable and ROC analyses, although attenuation was observed in multivariable analysis.
Conclusion: QTc and Tp-e parameters may provide useful information for ventricular arrhythmic risk assessment in patients with NIHF. Larger prospective studies are needed to validate their independent predictive value and clinical applicability.
Keywords: Non-ischemic heart failure; QT interval; Tpeak–tend interval; Ventricular arrhythmias.
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