Predictive Value of ECG Plane QRS-T Angle in the Long-term Tachyventricular Arrhythmias in Patients after Cardiac Resynchronization Therapy

LIANG Chunhui; ZHOU Sheng; HUANG Jiali

doi:10.12102/j.issn.1672-1349.2026.01.019

Abstract：Objective: To explore the predictive value of the planar QRS-T angle for long-term rapid ventricular arrhythmias (VTA) in patients undergoing cardiac resynchronization therapy (CRT). Methods: A total of 421 patients with chronic heart failure (CHF) who received CRT at our hospital between March 2020 and March 2023 were enrolled. According to the follow-up results at 6 months post-surgery, the patients were divided into a VTA group (154 cases with VTA events) and a Non-VTA group (267 cases without VTA events). Clinical data and planar QRS-T angles were compared between the two groups. Univariate logistic regression analysis was used to assess the correlation between the reduction in the planar QRS-T angle and the incidence of VTA. Restricted cubic spline analysis was performed to evaluate the association between the planar QRS-T angle and the probability of VTA occurrence. Multivariate logistic regression analysis was conducted to establish a predictive scoring model based on the planar QRS-T angle after adjusting for confounding factors. The model was validated using Bootstrap resampling (1,000 repetitions of the original data). Results: Compared with preoperative values, the QRS-T angles at 3 days and 6 months post-surgery were both decreased in both groups (P < 0.05). The QRS-T angles at 3 days and 6 months post-surgery were higher in the VTA group than in the Non-VTA group (P < 0.05). Compared with the Non-VTA group, the proportion of patients with a QRS-T angle reduction greater than 20° was lower in the VTA group, while the proportion of patients with a reduction less than 10° was higher (P < 0.05). Univariate logistic regression analysis showed that as the reduction in the QRS-T angle increased, the probability of VTA occurrence decreased. When the planar QRS-T angle was greater than 80° at 3 days post-surgery, it showed a significant positive correlation with the probability of VTA occurrence. Multivariate logistic regression analysis showed that low-density lipoprotein cholesterol (LDL-C), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and left ventricular ejection fraction (LVEF) were confounding factors. After adjustment, the planar QRS-T angle at 3 days post-surgery was an independent risk factor for VTA occurrence. The regression coefficients of the QRS-T angle were greater than those of LDL-C, NT-proBNP, and LVEF. Compared with other clinical indicators, the QRS-T angle had a higher predictive value for VTA occurrence. A risk stratification model was established by assigning 5 points as the main weight to a planar QRS-T angle greater than 80°. The higher the total score of the model, the higher the probability of VTA occurrence. Model validation showed good discrimination, with an area under the receiver operating characteristic (ROC) curve of 0.928 [95% CI (0.858, 0.998)] and 0.926 [95% CI (0.854, 0.997)]. The calibration curve showed high accuracy of the model. Conclusion: The planar QRS-T angle is an economical, non-invasive, and easily measurable parameter in 12-lead electrocardiograms. The postoperative QRS-T angle has a higher predictive value for long-term VTA risk in CHF patients undergoing CRT compared to the baseline QRS-T angle. The degree of reduction in the postoperative QRS-T angle is significantly negatively correlated with the risk of VTA occurrence. After controlling for confounding factors, a planar QRS-T angle greater than 80° is an independent predictor of VTA occurrence.