Department of Cardiology, Manisa City Hospital, Manisa 45040, Turkey.
Department of Cardiology, Sancaktepe Sehit Profesor Ilhan Varank Education and Research Hospital, Istanbul, Turkey.
J Electrocardiol. 2021 Sep-Oct;68:24-29. doi: 10.1016/j.jelectrocard.2021.06.015. Epub 2021 Jul 3.
It is practical and useful to detect patients who benefit from cardiac resynchronization therapy (CRT) by electrocardiographic (ECG) methods. In this study, the predictive role of the frontal QRS-T angle and other ECG parameters was evaluated in CRT responder patients.
Seventy-seven consecutive patients with left ventricular ejection fraction (LVEF) ≤ 35%, New York Heart Association (NYHA) classes II-III, ambulatory class IV and normal sinus rhythm, who had complete left bundle branch block and were treated with CRT were included in this study. Patients were classified as "CRT responders" and "CRT non responders" according to their LVEF improvement. The frontal QRS-T angle was calculated as the absolute value of the difference between the QRS and T wave axes [frontal QRS-T angle = (QRS axis-T axis)].
The mean age of the patients was 64.5 ± 9.1 years, and the average follow-up was 28 (12-47) months. The post-implantation LVEF was higher in the patients CRT responders group (p < 0.001). Post-implantation frontal QRS-T angle (p = 0.003), QRS duration (p = 0.008) and cQT interval (p = 0.012) values were much shorter in the CRT responder group. Multivariable regression analyses showed that the frontal QRS-T angle and age were independent risk factors for CRT response (p = 0.009). The results of the receiver operating characteristic curve analyses (ROC) showed that the predictive optimal cut-off value of CRT response for the frontal QRS-T angle was <135 degrees (AUC: 0.69, 95% CI 0.575-0.814, p = 0.004).
The narrowed frontal QRS-T angle (<135 degrees), QRS duration and cQT interval were associated with CRT response in heart failure patients. The frontal QRS-T angle can be an independent predictor of CRT response.
通过心电图（ECG）方法检测受益于心脏再同步治疗（CRT）的患者是实用且有效的。在这项研究中，评估了额面 QRS-T 角和其他 ECG 参数在 CRT 应答者患者中的预测作用。
本研究纳入了 77 例连续的左心室射血分数（LVEF）≤35%、纽约心脏协会（NYHA）分级 II-III、有间歇性 IV 级症状和正常窦性节律、完全左束支传导阻滞并接受 CRT 治疗的患者。根据 LVEF 的改善，将患者分为“CRT 应答者”和“CRT 无应答者”。额面 QRS-T 角定义为 QRS 波和 T 波轴之间的绝对值差[额面 QRS-T 角=（QRS 轴-T 轴）]。
患者的平均年龄为 64.5±9.1 岁，平均随访时间为 28（12-47）个月。CRT 应答者组患者的植入后 LVEF 更高（p<0.001）。植入后额面 QRS-T 角（p=0.003）、QRS 持续时间（p=0.008）和 cQT 间期（p=0.012）明显缩短。多变量回归分析显示，额面 QRS-T 角和年龄是 CRT 反应的独立危险因素（p=0.009）。ROC 曲线分析结果显示，额面 QRS-T 角预测 CRT 反应的最佳截断值为<135 度（AUC：0.69，95%CI 0.575-0.814，p=0.004）。
心力衰竭患者 CRT 应答与额面 QRS-T 角变窄（<135 度）、QRS 持续时间和 cQT 间期缩短相关。额面 QRS-T 角可作为 CRT 反应的独立预测指标。
