Association between QT dispersion and ventricular ectopic beat burden in patients without structural heart disease

Aims: Ventricular ectopic beats (VEB) are among the most frequently encountered rhythm abnormalities in clinical practice. Although generally considered benign, increased VE burden may indicate underlying electrophysiological instability. QT dispersion (QTd), a non-invasive electrocardiographic marker reflecting regional heterogeneity of ventricular repolarization, has been suggested as a predictor of ventricular arrhythmias. This study aimed to investigate the association between corrected QTd and VEB burden.Methods: This retrospective cross-sectional study included adult patients (≥18 years) who presented with palpitations between July 2023 and July 2025 and underwent both a standard 12-lead ECG and a 24-hour Holter ECG recording. Individuals with structural heart disease, coronary artery disease, arrhythmic medications, or reduced EF (<50%) were excluded. The final analysis included 301 patients, divided into two groups: frequent VEBs (≥100 in 24 hours, n=212) and infrequent VEBs (<100, n=89). QT intervals were measured manually, and QTd_corrected was calculated as the difference between maximum and minimum QT intervals values using Bazett’s formula. Clinical, biochemical, and echocardiographic parameters were retrospectively collected. Comparative analyses and linear regression were performed to evaluate predictors of VEB count. Additionally, ROC analysis was used to identify the optimal QTd_corrected cut-off.Results: The QTd_corrected was significantly higher in the frequent VEB group compared to the infrequent group (65.79 ± 14.85 ms vs. 60.88 ± 14.98 ms, p=0.009). In multivariate linear regression, QTd_corrected was found to be an independent predictor of VEB count (β=0.200, p<0.001). ROC analysis revealed that a QTd_corrected value >62 ms predicted high VEB burden with 71% sensitivity and 70% specificity (AUC = 0.734, 95% CI: 0.670–0.798).Conclusion: QTd_corrected was significantly and independently associated with VEB frequency in this cohort. This finding suggests that QTd_corrected may serve as a practical and non-invasive tool to estimate arrhythmic burden, especially in patients without structural heart disease.